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Unexplainable damp patch?! which trade do i need? what should i check?

Posted by michelle white, on
I have an unexplainable damp patch in an upstairs bedroom Its at the top of the wall, close to an external wall. the roof and guttering both look fine but I'm far from being an expert!! what else should i be checking? what trade do i need to come and investigate the problem? builder or roofer? Thanks
Sergejs Leonovs

Sergejs Leonovs

Hi Michelle -Firstly: roofer must check the gutters and their compounds, maybe they are clogged various debris and rain water flows over and gets on your exterior wall -Secondly: The builder must check the condition of the exterior walls (to determine which year of construction, condition of bricks, cracks, etc.) -About condensation, it is often a misconception by trying to explain why, as follows: Condensate (Latin condensatus - compact, condensed) - a product of condensation of vapor of liquids, the substance is a product of the transition upon cooling of the gas to a liquid. The coldest place in the apartment, it's a different kind of windows and doors. Speaking of the interior walls (they have a higher temperature than that of the windows and doors), they must be completely covered with condensation, ie damp. The use of a washing machine, drying wet clothes, you see, our apartments are not laundries, where this is an ongoing process - may not be sufficient cause of the wet spots,sorry I repeat not the entire area of ??the wall, and specifically some sections of the wall. I think that you are able to answer your question. many different causes of dampness Regards Sergejs
Abraham Rossiter

Abraham Rossiter

Hi Michele it may be several things but the most likely would be that your felt has deteriorated and fell just short of your guttering meaning any wind can blow the rain water beneath your tiles and below the felt level. I believe that you need a roofer.

Andy Pearce

Hi Michelle Damp patches that appear in random places like your one are mostly condensation, as this will be a cold spot and any damp in the air will attach to the cold parts of the room. This is caused if you dry clothes on radiators or have a tumble dryer that is non condensing or even leave wet clothes on the floor by the washing machine. Try to leave windows open when you can as good ventilation will help. If it gets any worse there is a electric PIV loft unit that will give a good balance to the rooms and rid the air of all damp, however these are a last resort due to the price (£350.00) but are extremely effective. The only other explanation for random damp patches is penetrating damp but it seems unlikely and almost impossible if you have cavity walls. Hope this helps Andy
Brian Joseph Lenehan

Brian Joseph Lenehan

Hello, I myself had the very same problem in a property i own and the problem turned out to be the gutter. The gutter looked fine but upon closer inspection the joint above where the damp patch was had been leaking rain water. I decided to use gutter / drain pipe adhesive, which I applied quite liberally to the joint. The plaster dried out in about two weeks. Problem gone Thank you
Thomas Lyon

Thomas Lyon

a roofer or a builder should be able to find the source of the problem but would need a proper investigation by means of a ladder or scaffolding cant tell a lot from the ground
Louis De Courcey

Louis De Courcey

This sounds more likely to be a external masonry breakdown on the pointing and brickwork , look for signs of cracking or mortar missing .
Chris Plastow

Chris Plastow

Is there any chance that there was a chimney on that position originally ? This damp spot could be ammonium sulphate contamination from the back of an old chimney flue . This condition is called hygroscopic dampness , it's often more visible in winter and disappears slowly in summer unless the humidity is high . The patch is often quite well rounded and can be slightly yellow . I would say a damp proofer , CSRT surveyor is needed or this could be expensive and frustrating .

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