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Rising damp conflicting suggestions from builders

Postby sarahholder » Wed Mar 05, 2008 11:05 am

Hi, in my Victorian mid-terrace house, the kitchen has never been heated and so it's cold and we're in process of renovating and there seems to be some condensation on the interior walls, with the outside wall possibly damp and a chimney breast with crumbling mortar coming off the bricks.

1. Damp proofing company said there was damp all round, even on internal party wall, but it really doesn't look it, and they'd damp proof it all, hack off old plaster half way and rerender and plaster, and they would "tank" the chimney breast with slurrytex. Cost £1600.

2. Builder with damp proofing experience said he wouldn't damp proof course, no point, and would hack off all render on all walls and chimney breast, and replace with waterproof sand and cement floor to ceiling and skim plaster. Cost £1500

3. Two separate plasterers have said they reckon it's just condensation over 100+ years, and they would simply install heating in the kitchen, ensure it's well ventilated (which we are doing) and skim plaster over the old walls,and sand and cement the chimney breast. £500 -£700.

HELP??!!!! I don't know who to believe and what to do.

I can believe there may be some damp on outside wall, as a part of it is below ground level, but it seems excessive to damp proof all the walls as they look fine to me, but at the same time i don't want to spend £700 and have money wasted when black mould appears thru new skim plaster!

I would really appreciate any thoughts, advice, etc
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Simply Build It

Postby Perry525 » Fri Mar 07, 2008 7:13 pm

When your home was built, it was made with things that were not/are not in themselves water proof. Bricks, slates are merely designed to shed water.
It would not have been designed or built to be dry.
It would have been expected to get damp and dry out again many times over its life - and it has.
It may not have a damp proof course, have you checked?

Condensation. This is something you create in a home by being there. every hour you breath out about 46 grams of water. Its estimated that over a 24 hour period each of us puts 2.5 litres of water vapour into our home. Children who are more active add more!

Taking a shower, cooking not closing the bathroom door when there are wet towels on the radiator all add water vapour to a home.

Water vapour will condense into your bedding, clothes, everything.

Its usually visible as condensation and damp patches on windows and walls, any cold patch will attracted damp.

The solution, buy a de-humidifier one that takes about 10 litres of water vapour out of the air every 24 hours. turn it on, leave it on, especially overnight, when the cold outside lowers the wall and window temperature and encourages condensation.

Final point, heat the room, keep the temperature constant, warming the walls and the contents of the room will help stop the water vapour condensing.

In a few weeks the room will be nice and warm and dry.

On the other hand just wait for the warm days of summer, the problem will go away until the winter.
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