Archive for the ‘Damp’ Category

Advice on gutter replacement

Tuesday, March 26th, 2013

Inappropriate brackets caused this new plastic gutter to sag before the building was complete

Water is the enemy of buildings; it will saturate walls allowing frost to shatter the masonry and mold to grow internally; it will accelerate the deterioration of paintwork and cause joinery to rot.

Most water comes in the form of rainfall, falling on roofs then being carried away in gutters and downpipes eventually discharging into main drains or soakaways.

The weakest link in the chain is the gutters. They collect all the water that falls on the roof to carry it away from the building. Sadly, all too often, ignorance, short cuts and penny-pinching results in lack of maintenance or inappropriate replacements.

Have you ever been out in the rain to look around your property? Try it sometime; any gutter leaks will be obvious. Even on a dry day a trained eye will spot sagging, twisted and misaligned gutters, some leaking joints and the tell-tale signs of gutter leaks and damp-affected walls.

A common failing is the replacement of old cast iron gutters with cheap plastic.

Plastic gutters are fine as long as they are properly supported and the proprietary brackets are used.

The grooves and tabs on this proprietary bracket grip and stiffen the plastic gutter

When used as replacements for cast iron the plastic gutters are often laid in the old metal rise-and-fall brackets resulting in premature failure for two main reasons:

1. the brackets are spaced too widely. Iron gutters are rigid and self-supporting but plastic is flexible and needs more frequent supports. The lack of adequate support allows the gutters to twist and sag resulting in overflowing and also causing joints to fail.

2. the old brackets that acted as ‘cradles’ for the heavy iron gutters do not ‘grip’ the plastic gutters, as do the proprietary gutter brackets, resulting in the plastic gutters sagging, twisting and overflowing due to their flexibility. Proprietary plastic brackets ‘grip’ the gutters acting as stiffening ribs, making the gutter rigid and secure.

Do you know a good builder who can fix my problems?

Tuesday, February 12th, 2013

Would a couple of vent grilles get rid of this black mould?

Cracks in the wall, damp, black mould – all common building problems.

But how to get them fixed? I know, let’s call a builder for a free quotation.

But a builder will treat the symptoms without fully understanding the cause; you could waste £000’s on a ‘fix’ that’s not needed or might fail.

But don’t blame the builder; it’s not his fault; anyone can call himself a builder or a specialist in ‘this’ or ‘that’. He might be a trained bricklayer or joiner but he’s not trained to understand how buildings work and why they fail; that is what surveyors do.

A surveyor will investigate the underlying cause and tell the builder what to do to put it right.

For example, a friend recently asked me to look at a black mould problem in a small 1960s terraced house. He had two quotations from ‘specialist’ damp contractors. Both were offering their own different ventilation solutions at hugely different prices. Which one should he use?

I checked the place out and, as expected, found the house full of warm moist air from showering, cooking, laundry etc. Yes, ventilation was required, but that was not all.

The contractors’ solutions were only the starting point. Their venting proposals were inadequate alone and wouldn’t cure the problem.

They made no mention of the need to insulate the cold spots, fix the leaking rainwater pipe nor suggested ways to reduce the build-up of moist air in the house.

The same goes for cracks in walls and rising damp.

Most cracks are insignificant, the result of thermal movement or minor settlement, and require little or no remedial work. But a bullder will fix it for you!

And true rising damp, as a result of failed damp-proof courses, is very rare too; there is nearly always an underlying cause. I’ve seen leaking gutters, a running overflow and a split dishwasher hose all identified as ‘rising damp’. And until someone can explain to me how injecting chemicals into solid, hard, impervious clay bricks can create a damp-proof course I shall remain ever sceptical.

A builder’s advice might come for ‘free’ but what is the cost if he gets it wrong or the work is unnecessary? And he’s hardly impartial.

A surveyor will charge but he is knowledgeable, impartial and more likely to get things right….. and if it goes wrong you can sue him.

Patchit & Bodgit Builders do more harm than good

Thursday, November 1st, 2012

Ugly cement mortar will damage the stone

A recent survey of a Grade II listed stone church yet again confirmed how advice from a builder can be fraught with problems.

They say “A little knowledge is a dangerous thing” and it certainly is!

Leaking gutter joints had been patched with an adhesive tape material. It may last a while if the rust has been well cleaned; but what chance of that?

The gutters had been repaired but the split rainwater pipes had been ignored!

Those issues are relatively minor; they can be easily remedied. And the gutters and pipes will need replacing in due course.

The greater sin was the ‘repointing’. The dark grey cement mortar, smeared all over the fine honey-coloured stonework is unsightly and has disfigured the walls. But worse than that, it will lead to accelerated deterioration of the stonework.

Mortar joints are designed to be ‘sacrificial’; they erode in preference to the stone. It’s much easier and cheaper to repoint a wall than to replace the stones.

Sandstone is relatively soft compared with clay bricks or concrete blocks, so a lime-sand mix is traditionally used; it’s weaker, permeable, lighter in colour and much more ‘forgiving’; small cracks in the joints will tend to heal themselves.

The strong cement mortar used is harder than the stone and the existing lime mortar; it is impermeable so moisture can be trapped behind it. Trapped water will freeze and shatter the stone. Salts in the trapped water can crystalize; the crystals will grow and force stone particles break-off – erosion.

Anyone can buy a van and be a builder; a Chartered Surveyor has many years of formal training in their specialism, and at Barlow & Associates we have many years of experience too.

Chemical damp-proof courses – Cure all or Catch all?

Wednesday, February 29th, 2012

Useless dpc inserted well above floor level

You must have seen them; tell-tale rows of mortar spots or brown plastic caps running from one end of the street to the other. Our terraced housing stock is full of them.
Soundly built, often with hard clay bricks, such homes have stood for over a century without rising damp; so why now?

Built with open fires and no central heating, with draughty sash windows, not sealed upvc and on washdays the back door wide open to let all the steam out. The houses could ‘breathe’. Draughts blowing in round the windows shot up the chimney taking the moisture-laden air with them.

Modern living and ‘saving the planet’ has put an end to all that. Those sturdy old houses are now molly-coddled with draught-proofed windows, loft insulation, they’re now hermetically sealed boxes in which we shower, cook and breathe out moisture-laden air.

The bricks haven’t changed, nor have the ground conditions or the coal cellars would be flooded, so why have the walls become so damp? Condensation Doh!

Our over-heated, super-sealed homes store up the moisture with no way out but to condense on the coldest place in the room – low down on the outside wall. And to make matters worse this is just the place, under the window, where years of condensation on old single-glazed windows, with no window cill to speak of, has run-off onto the plaster.

Old plaster under windows, even under the bedroom windows, is often loose or perished, the result of condensation from old windows, and I defy any rising damp to rise that high.

So why all the fuss? Why install a new dpc? Usually because some ill -informed mortgage lender insisted when his valuation surveyor reported the lack of a dpc.

And why wasn’t this error highlighted and the malpractice stamped out? Because inexperienced surveyors ‘copped-out’ and recommended referral to and ‘expert’, and the ‘experts’ were the very companies selling the product! It was a money machine.

And, to make matters worse, if you really had rising damp the stuff was no good and badly installed.

Tests have shown clay bricks are so dense that it is almost impossible for water to rise through them; the mortar bedding or the plaster facing are the most likely paths.

Clay bricks are so dense that hardly any of the damp-proofing solution can be absorbed anyway; not enough to block all the pathways, if there were any.

And so what if the wall gets a bit damp? It could rot any joist ends built in to the wall. But the joists in most terraced houses run side-to-side not front –to-back.

Even then, how often have you seen the neat row of holes half way up the front wall, way above the floor joists? They’re there just for show.

If you think you have a damp problem remember that ‘rising damp’ is Very rare. There is usually some other cause like condensation, a leaking gutter, a split rainwater pipe or a leaking washing machine hose to name but a few so, if you can’t find the cause yourself give us a call.

Black Mould

Monday, February 14th, 2011

Black mould can be a constant source of distress to many homeowners.

It is especially common in older properties, which are poorly insulated and ventilated and which have been ‘modernised’ to provide central heating and showers, draught stripping and double glazing.

Black mould on cold surfaces

Black mould normally occurs due to condensation; that is where warm, moisture-laden air condensates on cold surfaces creating a damp environment in which the mould can grow.

Bathrooms, bedrooms and kitchens are the most common rooms to suffer and small bungalows or big old houses can suffer in equal measure.

There is no single cure.  Each incident must be considered on its merits but the main requirements are:

  1. Good extract ventilation to remove the moisture laden air quickly
  2. Good insulation to prevent wall surfaces from getting too cold
  3. Good heating to warm wall surfaces

A common fault is that bathroom fans are often undersized or linked to the light switch.  This is a mistake, they need to be sized to extract the steam quickly, not just to provide background ventilation and they need their own switch so they can operate when the light is switched-off.

Bathrooms should also be ‘overheated’.  Don’t be afraid of installing a large heated towel-rail radiator and make sure it’s free from any thermostatic controls.

For further information and advice contact Chris Mills on 01332 603000.

Builders Build; Surveyors Survey

Monday, January 31st, 2011

The roof is sound but water leaks through erroded joints in the stone parapet

Damp is the enemy of buildings.  While it stays outside it is largely ignored but when it leaks inside panic sets in.

I was called recently to a delightful Georgian house  on the fringe of the city centre.  Water was pouring-in through the ceiling in two rooms and other rooms were slightly affected. 

Some years ago a roofer had advised the owner to re-roof the property but, inspite of subsequent ‘repairs’, the leaks have persisted.

I checked-out the roof; it was an OK job, not the best, but it certainly wasn’t the cause of her leaks.

It took only a few minutes to identify the perished stonework in the parapet wall as the culprit.  Joints are open and stones are badly eroded.

I know a good local builder with some exellent stone masons who I know will be just right for the job.

It’s ‘Horses for Courses’.

A roofer knows about roofs;  a mason can build you a wall, but rarely do tradesmen have the all-round knowledge required to cross the boundaries of their trade; an expert surveyor does!

The Last Staw!

Tuesday, December 14th, 2010

There was a first for me last week in more years than I care to admit to as a surveyor.

The call came from a client in North Derbyshire with a modern house on a large estate.  Tiles were falling off his bathroom wall and the room was full of flies.  His wife and daughter were giving him grief because they couldn’t use the shower.

It was clear that water from the shower had got through the seal around the bath edge and soaked into the wall.  The paper face on the board beneath (plasterboard I first thought) had disintegrated and turned into a black ‘mush’  leaving the tiling with nothing to stick to.

But what about all the flies?  Dozens of very tiny midges.  Where were they coming from?

Removing the bath panel the floor looked more like a hen house; straw everywhere.  It wasn’t plasterboard at all, it was a straw-board partition!  Clearly, the moisture had caused the straw to decompose; it was like having a compost heap for a wall, hence the infestation of flies, breeding in the ‘compost’.

There was no option but to tear the wall down and rebuild it in moisture resistant board.

The wall was rebuilt, retiled and redecorated in a fortnight with smiles all round.