Be Your Own Surveyor, External Walls – Inside.

Richard Greenland

There are three main types of damp and outside walls are prone to all. I’ve already covered this in detail in previous blogs.

In summary, rising damp doesn’t usually travel beyond 1.2 metres above ground level unless the masonry is very hydrophilic (attractive of moisture). It shows itself by damage to plaster and efflorescence. This is white crystalline deposits of sulphur and carbonate salts from soil or masonry, dissolving in moisture and coming to the surface, giving a blistered appearance to the plaster. It can be treated by injection (£500 or more for a typical terrace).

Penetrating damp can also cause efflorescence. It can appear anywhere, from multiple causes. Faults with masonry include porous stone or brick, loose render (the cement outer coating of the wall) and deteriorating pointing (the cement finishing between bricks or stones). These may require scaffolding to rectify and can be expensive.

Penetrating damp unconnected to the masonry includes leaking gutters and downpipes, dripping overflow pipes, leaky roofs, water splashing over the hopper where the gutter joins the downpipe, and earth piled high against outside walls acting as a conduit over the damp-proof membrane (DPM). Most are easily and cheaply rectified.

The third type, condensation, appears on cold surfaces such as single-glazed windows where it runs down and damages the sill and walls to the sides, or on outside walls where ventilation is poor, such as behind wardrobes or inside cupboards. Insulating well and removing furniture from outside walls, plus putting in a mobile dehumidifier, will help.

Other issues are corroding metal wall ties on early 20^th century cavity walls. Early cavity wall buildings up to the ‘40s or ‘50s are prone. Modern ties are galvanised or plastic, and designed so that condensation doesn’t settle but drips off the middle and down the cavity. It can be very expensive to get remedial work done. Unfortunately there’s no simple way of telling unless the brick skins have already started to separate and become unstable.

‘Concrete cancer’ is a problem of system-built (prefab) buildings from the mid 20^th century, with pre-cast concrete walls. It’s caused by efflorescence of salts damaging the concrete and corroding the reinforcing rods. That’s why these buildings are generally unmortgageable, although many may be structurally sound.

Modern houses should have out-and-down facing cavity trays of plastic or lead above openings (windows and doors), cavity closers at the sides and a folded-over plastic DPM underneath. This prevents water migrating from outer to inner skin across the cavity at the window reveals (sides). If there is evidence of damp migrating in around openings, the trays may be faulty or missing.

I’ll write about assessing wooden floors next week.

All the best,

Rich

Tags: external walls, Masonry, rich
Posted in Repair Free Rentals on August 24th, 2010 |

Be Your Own Surveyor, External Walls – Outside.

Richard Greenland

Most UK homes have walls of masonry, e.g. brick, block, stone or concrete, either with or without a cavity. The cavity separates the damp, cold outer layer from the dry, warm inner layer. There are exceptions using modern timber framing methods, and Elizabethan houses are often timber-framed with a cavity, so it’s nothing new! Cavity wall insulation really helps keep the inner skin warm and condensation-free. Most homes built before about the second decade of the last century have solid walls. If masonry walls are about 9 inches thick or less they are solid (a brick is 4 inches thick, so two bricks plus plaster = about 9 inches). Thicker walls doesn’t necessarily indicate a cavity as earlier homes were often built with very thick solid walls.

The first check should be whether the walls are plumb. If there is significant lean it’s usually perceptible to the eye. You can visually line up the edges of the house with other buildings as a rough gauge to see when walls are out of plumb. Are the two edges parallel? To check if it’s your building that’s leaning, dangle a plum bob (a bit of string with a weight attached) out of an upstairs window. If it’s parallel to the wall, all well and good. If the variation between top and bottom is more than a third of the thickness of the wall, it’s potentially unstable. I wouldn’t necessarily leave a house because the walls were leaning slightly, particularly if they were very thick, but it could be due to subsidence. If unsure get a structural engineer’s report. Underpinning if needed will cost several hundred pounds per linear meter, depending on depth, access, soil type etc

Another cause is that roofs can push them out. The rafters are diagonal and press out sideways on the walls, unless they are tied in at the bottom by ceiling joists which are continuous throughout the whole width of the house. Tying them in is not complicated, but re-righting leaning walls is generally impractical.

A little surface cracking of render is usually due to thermal movement as the building expands and contracts over the seasons and at different times of day. They are nothing to worry about, just a reminder of where someone should have put an expansion joint but failed to do so! Cracks more than three or four millimetres wide can indicate ground movement of the foundations. This is also indicated by the courses (layers) of bricks becoming uneven and out of level. Go to the edge of the building and look along the mortar joints. Are they straight and level? Or do they dip at piers and rise at windows? The latter indicates that the heavier parts of the building are sinking on it’s foundations. If the building has been rendered, you can look along the window sills, or along any coping. Again, a little movement isn’t necessarily a concern, especially if the building is over 100 years old and most of the movement may have occurred early in its life.

Render (a wall-coating of sand-and-cement) should be checked for adhesion to the wall by tapping it with a screwdriver handle or similar. If it sounds hollow, it may be partly detached and need replacement. This can let water in. Try scratching it with an old screwdriver, if you can easily it’s too soft. In a misguided attempt to save money, some buildings are rendered with as little as 1 part cement to 12 parts sand, which is far too weak, porous and soft. It’ll need chipping back and replacing with a minimum 4:1 mix and a waterproofing additive.

If the masonry is unrendered, check the pointing (the outer layer of harder cement in the joints). Is it loose or missing? Are the bricks or stones themselves crumbly from frost or wind damage? Soft, cool-fired bricks are particularly prone to this, as are Yorkshire gritstone and schist. This can allow moisture penetration. Rendering is generally cheaper and more reliable than re-pointing. A bonding chemical called SBR is used to prime the masonry. If walls are very loose, sheets of perforated metal (expanded metal lath or EML) should be bolted to the walls to provide an adhesive base. With scaffolding this can be quite expensive.

I’ll write about inspecting external walls from the inside next week.

Rich

Tags: Cavity wall, external walls, rich
Posted in Repair Free Rentals on August 17th, 2010 |

Be your own Surveyor – Solid Internal Walls.

Richard Greenland

I blogged about timber-frame internal walls last week, this week it’s solid internal walls. Older houses will usually have lime mortar, which is much softer but less prone to cracking (it absorbs the movement). Modern houses will have cement mortar.

Many of the same things apply as for timber walls. Use a spirit level to check door frames for level. Also look out for wallpaper crinkling diagonally at the corners where walls join indicating settlement (see last week’s blog).

EFFLORESCENCE

Rising damp is indicated by plaster becoming loose or peeling off below about 1.2 metres high, and by ‘efflorescence’, the appearance of fine carbonate and sulphate salt crystals on the surface, which often push through the plaster. These may need injecting with a silicone-based damp-proof membrane (DPM). A typical terrace can be done for about £500 but get competitive quotes. A few older houses have a slate DPM, which has been used since the time of the Romans!

Internal walls may have become overloaded by having large sections removed, for instance to knock a lounge and diner into one. This is indicated by diagonal cracking to the sides of the opening, as the walls compress where the lintels above are carried. Lintels should be on concrete padstones with a minimum bearing of 150mm. Sadly many original works in Victorian and Edwardian houses, or DIY works uncertified by Building Control, have a lot less. I have seen Victorian houses with very undersized wooden lintels, bearing on little more than the plaster! It’s a myth that old houses are better. They’re simply the ones that haven’t fallen down in the interim. Modern houses, with proper insulation, draft- and sound-proofing, and subject to the full scrutiny of Building Control, are in my opinion the best they have ever been.

Check if there are still chimneys outside but the chimney breast has gone from the rooms below. If so, what is supporting the chimney? DIY builders sometimes remove the supporting masonry leaving two tons of bricks teetering dangerously on the party wall. You don’t want to be living in a house like this when there’s a storm! I worked on a job in London where a man died when he attempted to remove a chimney from the bottom up and it collapsed on him. Ideally the chimney should be taken right out from the top (see my blog on roofs). Failing that it can be supported on lintels between the walls to either side, or cambered out from the party wall although this is less secure.

Finally, party walls. In modern houses they should be thick enough to avoid undue noise disturbance from next door. Older houses with two-brick thick walls plastered on both sides would normally pass modern acoustic tests. Unfortunately many older terraces only have party walls one brick thick and sound insulation is poor. Without drilling into the wall, the only way to tell is to listen when the neighbours are active and gauge how much noise there is.

I’ll write something on external walls next week.

Rich

Tags: Construction and Maintenance, masonry walls, rich, solid walls
Posted in Repair Free Rentals on August 10th, 2010 |

Be your own surveyor – timber internal walls.

Richard Greenland

I wrote about ceilings last week, this week I’m assessing internal walls, so take a long spirit level to gauge how flat, plumb and level the walls are. Doorways with unlevel heads may indicate settlement or subsidence. Another common indicator is wallpaper with diagonal creases where two walls meet. This can happen with any type of wall construction, and indicates that one wall has moved down relative to the other since they were papered. There will probably be diagonal cracks in the plaster underneath too. This isn’t necessarily a major problem in older, pre-building-regs houses with shallow foundations but which have stood the test of time. Particularly if the paper has been on for decades and hasn’t moved much. If unsure, get an engineer’s report. As I said in my blog about surveyors, for specific concerns an engineer is better than a surveyor’s report, as an engineer doesn’t just trouble-shoot but can suggest solutions as well.

As with ceilings, timber-framed internal walls come in two main types (plasterboard and lath-and-plaster). Walls may also be single-skin brickwork which I’ll cover next week.

Lath-and-plaster walls on a timber frame are subject to the same problems as ceilings which I discussed last week, except without the danger of concussing occupants by falling on their heads! They are easily damaged by impacts, the thin wooden laths flex on the frame, causing plaster to crack and fall away. Try pressing any indented bits with your fingers. If it moves easily it needs to come off and be replaced, either with a plasterboard patch or if more than about 10% of the total area then the whole wall. It’s not a big job, but skirting boards and architraves may have to come off, so get quotes. If lath and plaster walls are in good condition and bare of paper and paint, but just a bit rough, they can be revived with a quick skim of plaster (surprisingly, quicker, cheaper and better than lining paper).

cuboidal cracking

In many older houses timber-frame walls were built straight onto stone or concrete floors with no damp-proof-membrane (DPM) and eventually become riddled with rot and woodworm. If suspect, try the key test – pushing a long key (or screwdriver) into the bottom of any wood showing. If it yields easily, it’s rotten. If it shows signs of cuboidal cracking, it may have dry rot. The solution to the damp is to remove it all and replace on a plastic DPM to stop the damp. Dry rot is a bit more involved.

Little known fact – woodworm is also associated with damp. If you install central heating and reduce the relative humidity in the house enough, woodworm will die too. All creatures need moisture and if you deprive them of it completely they can’t survive. That’s why they congregate where timbers are damp.

As with ceilings, plasterboard walls should present fewer problems, so long as there are enough fixings and it’s dry.

Second little-known fact – timber walls can be load-bearing. Many times I’ve used a 4” x 2” timber frame wall to carry the floor above for a loft-conversion, to the complete satisfaction of the Building Inspector. If planning to remodel the house, don’t assume you’ll be able to pull out timber walls without putting in some kind of support for floors and walls above!

I’ll do solid internal walls next week.

Tags: Dry rot, internal walls, Lath and plaster, rich
Posted in Repair Free Rentals on August 3rd, 2010 |

One Response to “Be your own surveyor – timber internal walls.”

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Be your own Surveyor – Ceilings

Richard Greenland

Last week I discussed eaves soffits and fascia boards, this week it’s another type of soffits, i.e. ceilings.

Slightly saggy ceilings aren’t necessarily a problem, most older buildings have upstairs ceiling joists which are way undersized by today’s standards. These bow downwards especially if heavy objects are stored in the loft. Ceilings on downstairs rooms shouldn’t sag as they’re attached to the much thicker floor joists above. If they’re sagging, they need replacement – see below.

Ceilings and timber-frame screen walls come with two main types of covering. Lath-and-plaster is an old system of tacking rows of thin wooden strips between the joists then covering with lime and horsehair plaster. It sets soft and gritty with a thin pale top layer and softer darker underlayers. These are the ones which tend to fall down!

Modern timber ceilings are made of plasterboard – a sheet of plaster sandwiched between layers of thick paper. This is then screwed into place and plaster-skimmed. The top layer looks quite different to lime plaster, and should be smooth and even with a pink or grey colour.

Plasterboard ceilings probably won’t present problems unless they have insufficient screws/ clout nails. There should be fixings every 150mm to joists at the sheet’s edges and every 300mm to joists in the middle.

Old lath-and-plaster ceilings showing signs of irregular cracking or bowing can collapse suddenly on the occupants and are dangerous. Unstable ceilings need complete removal and replacement. If merely a bit suspect, and reasonably flat, I usually screw new plasterboard sheets underneath to hold everything in place and provide a better surface for my plasterer to finish. It saves masses of work and mess taking the old ceilings down, then putting it all back. You must be sure to put plenty of screws into the joists to secure the boards really safely. Your carpenter should be able to do two good sized bedrooms in 1 – 2 days, and your plasterer to skim both in a day. With materials it might cost £400 – £600 for two rooms. Artex can be steamed off or covered the same way – see my blog on this.

If the ceiling is very saggy in places your plasterer may not be able to skim, even if it’s covered with new boards. To check, place a straight board or spirit level about a metre long over any obvious bulges. If there’s more than about 25mm space at either end of the stick, it probably all needs to come down and have new joists and boards, and put all the insulation back too. This could easily cost twice as much or more than a simple board-over, and fibreglass dust is dangerous to lungs. Another less messy alternative is to build a separate ceiling underneath – good for reducing mess if the house is occupied, but it lowers the ceiling.

Some houses and tenament blocks have concrete ceilings (often beam-and-block), which should have few problems so long as the roof doesn’t leak. Uninsulated concrete is VERY cold and not good for tenant retention. It can be insulated with 2 x 2 battens or deeper, and sheets of closed-cell phenolic foam such as Celotex. Fibreglass is a relatively poor insulator at these thicknesses. If there are upstairs neighbours concrete can be surprisingly bad for noise transmission

Next week I’ll talk about internal walls.

Rich

Tags: ceilings, rich
Posted in Repair Free Rentals on July 27th, 2010 |

2 Responses to “Be your own Surveyor – Ceilings”

Ricky says:

August 1, 2010 at 6:36 am

This is great advice for anyone looking at renting flats, had a problem like this before and never noticed it until it came crashing down!

Reply
Rich says:

August 9, 2010 at 8:12 pm

I’m glad you found it useful. Yes, old ceilings falling down is not as uncommon as you might think and potentially very dangerous. There’s a lot of weight up there!

Reply

Be your own Surveyor- Fascias and soffits.

Richard Greenland

Fascia boards are the wooden or plastic boards behind the gutters under the eaves, or on the gable ends. Soffits are any surface which presents its lower side to the environment, such as a ceiling, but for the purpose of this blog I’ll refer only to those under the eaves.

Fascias in particular can get a lot of weathering, especially if the gutter leaks or overflows on them, and on south or west facing (windward) sides. Key places to look are therefore anywhere showing algae and staining from rainwater and behind the downpipe. Corners are also susceptible where timbers join, and the bottom of a gable end fascia board where water drains and can soak in. If you don’t have a ladder you probably can’t do the ‘key test’ mentioned in the windows blog (gently dig a key into the wood to see if it’s soft inside). But a localised patch of very cracked paintwork could indicate trouble. Fascia boards aren’t particularly costly to replace or mend off a ladder, less than a day’s work + materials for the odd repair, maybe £150. But my preferred solution is to cover wood with plastic sheathing, which might take a day plus materials (soffits and fascias) for a mid-terrace. Perhaps £200 – £250. It can be a LOT more costly if it’s too high or inaccessible for this and you need scaffolding.

FASCIA BOARD OVER ROOF EDGE, NOW COVERED IN PLASTIC.

Most fascia boards fit an inch or two underneath the roof, which is sensible. Some particularly troublesome ones on older buildings fit to the outer edge of the roof, with another board fitting on the top edge. These are inaccessible so poor maintainance is inevitable, leading to the board rotting. These are best covered or replaced with plastic fascia, with a special joint between lengths, or overlapping, to prevent water getting into the joints. It’s not a big job, perhaps £150 – £200, if scaffolding isn’t required, but due to the height it often is.

If fascias are very rotten the ends or sides of the rafters may also be affected, requiring more repairs. Eaves rafters can often be spliced. Gable end rafters will probably need replacement, but this isn’t usually hard as they are accessible on the outside of the building. This might only cost £150 or might run to over £1,000 depending how severe the damage is.

Check soffits on the outside corners of the building. Water leaking or splashing over the gutter, and fascias letting in water at the corners are common causes or rot here. Roofs leaking and sarking (roofing felt) stopping short of the gutter and emptying water into the eaves space is also common on older buildings. Birds like to nest inside the eaves and old nests can hold moisture and exacerbate the problem. Again soffits are not usually a big job to repair or replace, so long as scaffolding isn’t needed, see fascias above.

I’ll discuss ceilings next week.

Tags: fascia boards, rich, rot, soffits
Posted in Repair Free Rentals on July 20th, 2010 |

Be Your Own Surveyor, Damp Around Windows and Doors.

Richard Greenland

Last week I wrote about windows and doors and how to spot problems with them. This week I’ll cover their settings in walls, and particularly damp problems around them.

I’ve already written extensively on the four main types of damp – condensation, penetration, rising, and ‘devious’ which covers anything from Jackdaws nests to copper pipes weeping due to being set in corrosive cement.

Like chimneys in roofs, windows and doors are essentially holes in the walls and at constant risk of allowing moisture into the house. They are also cold-spots. Glass is colder than walls and drafts from them tend to cool adjacent walls. This causes condensation, usually in the bottom corners just above the windowboard (the extension to the sill which projects into the room). Water from condensation running off the glass can also puddle directly on the windowboard and damage plaster to the sides. Lack of double-glazing or poor insulation to the walls is the usual cause. Windows in a bathroom also need good ventilation, not covering with a blind as some of my tenants insist on doing!

Condensation damage at bottom of window opening

Damp patches under windowboards are probably penetrating damp. They may indicate a rotten sill allowing rain to soak into the walls. Use the key test mentioned last week. Repairing this is half – one day’s work for your carpenter. This problem should be rarer with modern buildings from the late 1980s on, which should have DPM under the sill.

Or damp under the windowboard could be caused by deterioration of the exterior silicone seal between the window /door frame and walls. Does it look fresh and flexible, or old and cracked? It’s easily replaced by scraping the old silicone off, priming any bare wood, then thoroughly re-sealing with exterior window silicone. Also check the stone or concrete subsill. If it’s cracked or sloping inwards and puddling, that could let in water. These faults are easily corrected with a bit of mortar.

You can prevent rain blowing in under doors with a ‘door drip bar’ or ‘door rain deflector bar’ (try googling these terms) at the bottom of the door outside and plenty of draft-excluders inside. You can also prevent rain blowing in over an outward opening door or window by fixing a thin metal one over the window. Alternatively a 2″ x 1″ wooden bar with a groove underneath to make the water drip off the edge will do. It’s a good idea to use a durable hardwood, and to slope the top of the bar outwards.

I may talk about fascias and soffits next week.

Rich

Tags: condensation, damp, doors, rich, windows
Posted in Repair Free Rentals on July 13th, 2010 |

Be your own Surveyor: Windows and Doors.

Richard Greenland

Last week I discussed gutters and downpipes, this week its windows and doors.

The first checks with windows and doors are obvious: Is there evidence of rot or damage? Do they open properly?

There are three main types:

White PVC double-glazing, wooden casements (hinged) and sashes (slide up and down). Contrary to popular belief, all these can be double-glazed by cutting the rebate (slot that holds the glass) deeper to allow for thicker glass. You also still find old galvanised metal casement windows from the 1970s and earlier, but thankfully they are becoming rarer. They are durable, but very bad for heat-loss and ideally need replacement.

The main problems with PVC windows are corroding or buckled hinges and runners, which can be replaced from the manufacturer if they are still in business. If not it may be possible to locate replacements over the internet as a few companies are starting to spring up offering replacement hinges. Otherwise you could end up paying for a whole new window! The other problem is the seal going on the D/G unit, evidenced by condensation between the glass. These are usually quick and inexpensive to replace. Some early PVC windows oxidised badly in sunlight, causing discolouration and brittleness of the plastic. It’s usually quite visible, these may need replacement.

Wooden windows also need checking for ease of opening and closing. Be careful! If there are no cords in a (sliding) sash window, the top sash may fall and smash on the sill when you open the catch. If unsure, it’s best to hold it up with one hand while slipping the catch. Stiff, rattly sash windows with frayed cords can be given a minor overhaul by a good carpenter in a couple of hours. The same goes for stiff hinges or jamming on casement windows. But if the timber is rotten it may require more work.

checking bottom corners for rot with a key

The commonest place for wooden windows to rot is in the bottom corners and under the sill, where it’s hard to see. Often the top few millimetres remains hard while the rot progresses internally. Try digging a key or screwdriver into the corners and any wood that looks flaky, uneven or cracked. If it goes in easily it’s rotten. At the very least it’ll need a patch, or possibly a replacement sill. With likely repairs to the stiles (sides) of the frame too, this could be a day’s work for your carpenter, plus materials. The best way to replace the sill is with durable hardwood, primed underneath to prevent moisture soaking into it, and with DPM (plastic Damp Proof Membrane) underneath, folded back to prevent water flowing over it into the house. (picture)

The bottom rail of the casement or sash (opening portion of casement or sash windows) often rots too. This is repairable, but if both sill and bottom rail need repairing, it may be cheaper to replace the whole thing.

Doors have similar problems, and wooden doors rot in similar places. Shamefully, exterior doors are rarely painted underneath (where it doesn’t show but is most needed), so premature rotting underneath is inevitable on many. A drip bar fitted along the front would help. Also check the ends of the middle rail on panel doors. These are very wide and expand and contract with changing seasons, often cracking along the grain and letting water into the joints. Door frames rot in similar places to window frames, and can be assessed and treated the same way. Replacing a front door and frame, plus the little window above if there is one, can easily be a couple of days work for a good carpenter, plus materials, particularly if the frame is built-in to the walls. All in it might cost £600 – £1,000.

If you have problems with a plastic door, you may have to improvise a repair or replace the whole thing. They require specialist parts to repair, but sometimes these can be found on the internet.

Next week I’ll cover damp problems around windows and doors.

Tags: Casement window, doors, doubleglazing, rich, Sash window, windows
Posted in Repair Free Rentals on July 6th, 2010 |

One Response to “Be your own Surveyor: Windows and Doors.”

Sharon says:

July 6, 2010 at 8:20 am

Can’t rate this series highly enough!
Thanks Richard!

Reply

Be your own Surveyor: Guttering and downpipes.

Richard Greenland

Guttering and rainwater downpipes ought to be very simple to assess and aren’t usually expensive to put right. But you need to be aware of them as they can cause very expensive problems with damp and rot inside the house.

A quick visual check: Do they look level? Corners in particular often drop, opening joints and causing overflows. If there’s a roof window, pouring a bucket of water out will show if it flows away correctly.

There are two main types, modern plastic and older cast iron (with new cast-iron and aluminium also available).

The main problems with plastic is UV damage, joint leaks and sagging. UV from the sun oxidises it and it becomes brittle. Gray plastic which looks very bleached on top may need replacement soon. Sagging occurs when there are too few clips (gutter should be clipped every 600mm). The sag causes water to puddle, and the extra weight causes more sagging. The deflection can make the joints work loose or water overflow and soak into the walls. Green algae stains at the joints or below them on walls, or peeling paint just below the joints, indicate leaks. The joints are push-fit only and can sometimes be repaired with some guttering silicone, or better by cannibalising the rubber seal from a new gutter-joint if you can find one which matches. Unfortunately there are many different makes and matching old material can be challenging!

downpipe partially embedded in corrosive cement

The main problems with cast iron are rust, joint leaks and downpipe blockages. Gutter sections are joined with a bolt and red-lead putty (very poisonous and not used today). If the gutter is too rusty it can be replaced with plastic, or with new cast if required for listed buildings. Signs of joints leaking are similar for plastic (above), plus rusty deposits and stains down the walls. They can often be repaired by cleaning out the joint, treating with Kurust, and re-sealing with special silicone and a new 6mm bolt. Cast sometimes leaks at the downpipes too, rusty deposits below the joint indicate this. Blockages occur because downpipes are undersize, below today’s standard 75mm. Also some disappear straight into the ground without an open grate and a ‘trap’ (U bend) to catch debris such as moss and leaves. If the house doesn’t have these, reckon on fitting them. A blockage below ground can back water all the way up the pipe where it squirts out of joints at high-pressure or sometimes even makes it to the top! Cast iron gutters set into masonry can corrode with the oxidising action of the cement, and invisibly leak into the walls. Ideally they should be open all the way round, but if there’s no evidence of damp inside there’s no immediate need to change them.

Another common problem is that a gutter becomes loose so that water discharging from the roof over or under-shoots.

None of these jobs are particularly expensive (unless using new cast iron or aluminium and/ or scaffolding). I usually do it off a ladder but not all builders are as confident with heights. On steeply sloping ground or with a third storey I want scaffolding, which puts costs up.

A quick note on building regs: Grey-water from sinks and baths etc should remain sealed from the air as it drains into the soil pipe. It isn’t supposed to go into an open hopper for health reasons, but it’s still permissible if it was built that way before the regs came in. Some areas have separate systems for storm- and waste-water.

Next week I’m considering assessing windows and doors.

Rich

Tags: downpipes, gutters, leaks, rich, roofs
Posted in Property, Repair Free Rentals on June 29th, 2010 |

2 Responses to “Be your own Surveyor: Guttering and downpipes.”

student loans says:

June 29, 2010 at 1:41 pm

Pretty nice post. I just stumbled upon your blog and wanted to say that I have really enjoyed browsing your blog posts. In any case I’ll be subscribing to your feed and I hope you write again soon!

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Richard says:

July 2, 2010 at 9:33 pm

Thanks SL! I try to write one every Tuesday, Nick or a guest blogger writes one almost every day.

BW,

Rich

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Be Your Own Surveyor – Chimneys and Parapets.

Richard Greenland

Last week I looked at common types of flat roofs and the problems they can cause. I didn’t mention good flat roof coverings of anodised metal and rubberised plastics, which are durable and often come with long guarantees, but are rare on domestic buildings.

Nor did I mention the very worst, bituminous felt/ chipboard. Condensation makes the chipboard sag, causing puddling on the roof above, making the felt stretch, causing leaking, making the chipboard sag more… Reckon on imminent replacement!

The pale stone chippings on bituminous roofs provide essential shade from the sun’s desiccating rays and will need replacement if missing.

Chimneys are attacked from inside and out by acids from burning coal, ferns, colonising plants and the weather. Loose pointing and plant life can easily be observed from outside. With deterioration they become porous and a conduit for moisture into the building. Problems with chimneys are indicated by a lot of sandy material coming down the chimney, a blocked ‘damper plate’ (openable metal flap above the fireplace) if there is one, or damp patches on chimney breasts or on ceilings above. This last could also indicate deterioration of the lead joining chimney to the roof or even birds-nest debris in the chimney.

The chimneys in my last project were so bad I could see daylight from front to back through the mortar gaps! I erected scaffolding, demolished them and roofed over the hole. This solved both problems of porous masonry and damaged lead-work. Taking them right down to ground level also made a lot of extra room in the house. If chimneys must remain, provided the lead-work is OK, the cheapest and most thorough waterproofing method is three coats of waterproof render. Repointing looks nicer but costs more and is less thorough. Unused chimney pots need capping to prevent rain coming in. You can tell which are in use by lighting a fire in the grate. Use a slate cut to size, preventing it being blown off, and weighted with a brick and a dob of mortar. Unused fireplaces can be blocked off but an air-vent should be fitted to reduce condensation. If fitting a wood-burning stove it’ll need lining.

three parapets through roofs on a modern building

Chimneys in newer buildings from the 1990s onwards should have lead trays or plastic DPM (damp proof membrane) continuing right through them, preventing water in the masonry above soaking into the walls below. Their chimney breasts should never become damp, but there’s no guarantee. The same goes for parapet walls, 1990s onwards should have no problems with porous masonry, although the lead joining it to the roof can still fail. On older buildings, if interior walls below the parapet are damp, removing the parapet and roofing over, as I did with my chimneys, is the best solution. Alternatively the parapet can be removed and rebuilt with a lead tray dressed through it and under the roof tiles. Failing this, renewing mortar in the joints between the capping slabs sometimes provides a partial solution.

Sometimes parapets and chimneys are blamed for penetrating damp of other causes. I recently looked over a block of flats for a friend, and although the parapets could have been the problem, to my mind the outside render (sand/ cement coating) was more suspect. It was very soft, perhaps only a 1:12 cement/sand mix, which would be very porous.

I’ll discuss assessing gutters and downpipes next week.

Tags: Chimney, parapets, rich, roof
Posted in Property, Repair Free Rentals on June 22nd, 2010 |

2 Responses to “Be Your Own Surveyor – Chimneys and Parapets.”

Christian Louboutin Sale says:

June 23, 2010 at 2:18 am

Thanks for your post,I have subscribe the newsletter,do these articles have copyright limit? can I post them in my blog?

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Richard says:

June 24, 2010 at 7:53 am

Christian, I’d rather you didn’t use content directly unless it is acknowledged with quotation marks and a link back here. One or two sentences (with acknowledgment and link) is OK but as I’m sure you’ll appreciate I don’t want the blogs lifted wholesale to somewhere else.

BW,

Rich

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