Damp Proofing Your Cottage

Damp Proofing Your Cottage The Easiest Ways

Solutions to Damp Problems in Cottages, Old Houses and  and Farmhouses.

Copyright (c) Lawrence Dyer 2011

Having owned and lived in a number of cottages I can tell you that getting the damp proofing of your cottage right as soon as possible is an important thing. Damp stains your walls, crumbles plaster, creates mould spores and breathing problems and rots your furniture, paper documents, beams and door frames. So damp proofing is something you need to get right as soon as possible from the date you take possession of your cottage or farmhouse.

If there is a problem with damp, that is, which there will be unless somebody else has already solved it for you (unlikely as most people don’t really understand how to sort out damp problems), or if the building’s original damp-proofing characteristics have survived and not been compromised.

There are basically three sources of damp which will cause problems in your old house or cottage. These are damp that comes up through the floor and the bottom of the walls (Rising Damp); moisture that finds a way in through the roof, around the chimney stack or through the walls (Penetrating Damp); and finally moisture that comes from kitchens and bathrooms in particular but can’t escape so settles on the walls and ceilings (Condensation).

The damp coming up from below, rising damp, is usually the hardest and most expensive to deal with, though severe roof problems can be expensive too. Whatever the cause, if you want a nicely decorated home with fresh clean air to breathe and no wet rot in the timbers then you are going to have to tackle any damp problems from the outset. Unfortunately there’s a lot of misunderstanding around how to tackle damp proofing in cottages, not least from a modern building industry that doesn’t understand the traditional materials such as stone and cobb that old buildings are made out of. I’ll let you in on everything I’ve learned and successfully applied over the years shortly, but first let me give you an example of what I’m talking about.

In one cottage I owned and was renovating with the help of a professional builder we had the problem of a very damp and mouldy wall upstairs in one of the bedrooms. The builder said he would renew the cement fillets along the edges of ther roof, although he felt that the existing ones were actually adequate. “To be honest, I can’t understand how water is getting in,” he said with a scratch of his head (we had already agreed that what we were looking at was some kind of penetrating damp).  The roof was an unusual one in this period cottage in that it did not overlap the tops of the stone walls as would be the case in most buildings, but the walls rose up a few inches higher than the slates of the roof and were topped by long, hand-shaped stones that formed a run-off for rain — a parapet, in fact.

So the builder renewed the cement fillets, but the problem persisted. He had no more ideas, he told me. I was at a loss too, at first. It was only when I got up on the roof myself and spent some time looking at the situation and doing some simple tests that I realised that rain water was finding its way through in two ways. Firstly it appeared to be soaking its way through the slightly porous shaped-stones of the wall-tops themselves and secondly it was certainly soaking through the cement fillets that filled the gap between the edges of the slates and the parapet wall-tops. In fact the addition of the first cement fillets by some cottager of the past was aggravating the situation. My solution at the time (ten years ago) was to brush on a transparent and invisible-when-dry water-sealing compound. This soaked into the surface of the stones and cement fillets and provided a barrier against rain. Within a week the wall was showing signs of drying out and the problem appeared to be solved.

However, I’ve since been informed by a period house pathologist that although my efforts constituted a temporary solution, the water-proofing compound will trap moisture in the top layer of the stone and cause it to decay. The cement fillets should have been removed and replaced with lead flashing.

An additional problem with the stone parapet is that this cottage is high up in the hills of the Peak District, a region of England that receives very high rainfall — so high, in fact, that people say a day doesn’t go by unless it rains or snows there. It may be that the removal of the cement fillets and replacement with lead flashing would have been enough to solve the problem, but it may also be the case that with the very high rainfall some minor moisture penetration would still occur, and the building had always suffered from its design throughout its 200 year life. If so, then I suppose a row of slates could be laid on the parapet to shed rain water.

Finally I should mention that the problem with this cottage no longer exists as an owner subsequent to me has removed the parapet and extended the roof over a modern extension.

To tell you everything I’ve learned about damp proofing in cottages and old houses I’m going to write three sections on solving damp problems, covering rising damp, penetrating damp and condesation problems. These are based on my own knowledge and personal experience of living in old buildings as I am not a trained specialist in the field:

  • Rising Damp
  • Penetrating Damp
  • Condesation Problems

The article contents represent the opinions and views of the author and are do not constitute any kind of advice. This article is legally copyright: if you wish to reproduce it you must contact the author to seek written permission; any other use of the article is unauthorized and in breach of legal copyright.

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