...where to position ventillation grills on damp wall

[friend of stouby]

 

Thank goodness for this forum, so much info here.

We have moisture in/on the inside of two of our outside walls which even with the current levels of dryness and heat is transferring moisture to fabrics, armchairs, towls and clothes hung outside a wardrobe.

This is probably the standard situation with 200 year old stone cottage, soil piled against the outside of 2 walls, part of the way down a slope, too old to have a damp course etc etc.

In the short term we want to improve the ventillation each room by fitting adjustable grills with ducts through the walls. 

The question is simple?? ...... is a grill more effective at floor level or ceiling level? have been trying to work out how air flow will be best created and can't decide if top or bottom is the best. Anybody have experience of this? Thanks in advance.

Jamie 

 

 

[tj]

[quote user="friend of stouby"]

 

We have moisture in/on the inside of two of our outside walls which even with the current levels of dryness and heat is transferring moisture to fabrics, armchairs, towls and clothes hung outside a wardrobe.

This is probably the standard situation with 200 year old stone cottage, soil piled against the outside of 2 walls, part of the way down a slope, too old to have a damp course etc etc.

In the short term we want to improve the ventillation each room by fitting adjustable grills with ducts through the walls. 

 

[/quote]

Hi

I am guessing that with increased ventilation you feel it will help take the moisture out of the air ?

I am also guessing that as you describe, old stone walls 60 cm plus, quite a job to install the vents, and in fact will not really help, and could make it worse in winter.

From what you say, it sounds like penetrating damp from the soil piled against the house, water passes thru the stone easily because its porous, inside the moisture is warmed and vapourised into the local atmosphere, on temperature changes, for example during the night the moisture then condenses on the colder surfaces, the walls, rather a vicious circle.

The simplest and most effective solution would be to remove completely and permanently the soil piles from the outside walls, if this is not possible then removing / digging out to provide a workspace, let the stone dryout and then a couple of coats of a bitumin sealer will do the trick.

In America most houses have a basement, when you build on a hillside, or a mountainside as I did in 2001, it is normal to have say the back wall completely in the ground and the two end walls within the sloping earth. There is usually no damp course either until the first level above the basement, except for the membrane beneath the concrete floor, after the block work was built to firstfloor level everything that was to be in the ground was bitumined, and then backfilled with earth.

just a few thoughts, hope it helps  

[Anton Redman]

If you have dry lined then one at the bottom and one at the top.