Rising Damp?

[Boisty]

Hi folks

A mate has asked me for help to solve what appears to be a rising damp problem along two walls of a converted barn.

The walls in question are in a room where the floor is lower than the ground outside and having dug a slim channel away about 12 months ago along the outside walls damp is still apparent inside.

I suspect that the wall has not had a silicon injected damp course as there are no tell tale holes drilled into the walls so that is going to be my next course of action however, the wall is a solid wall of about 15 inches thick and I am aware that to create a good silicon injection damp course it is necessary to inject into the horizontal mortar bed of both inside and outside courses.
My question is, how can I ensure that the internal structure, ie, the bricks inside the inner and outer skins receive the silicon to the mortar and not the the bricks?

Any advise on this would be appreciated along with any other ideas as to how I can solve this problem.

 

[dann09]

1. Is the "slim channel" a french drain?
How deep and wide is it?
Is it filled with stones?
Along the outside of the building - on how many walls?

2. Is there a membrane, below the floor, that can be seen lapping up the walls?

3. Is the interior plastered or rendered? Was it renewed 12 months ago?

4. Is the exterior rendered?

5. Injecting silicone might help, but there are many other factors to take into account.

6. Have you carefully inspected for an existing DPC - slate, bitumen etc.?





7. Have you researched your issues on here? In 2013 alone there have been a number of posts on precisely your issues.

 

[Boisty]

1. Is the "slim channel" a french drain?
How deep and wide is it?
Is it filled with stones?
Along the outside of the building - on how many walls?

2. Is there a membrane, below the floor, that can be seen lapping up the walls?

3. Is the interior plastered or rendered? Was it renewed 12 months ago?

4. Is the exterior rendered?

5. Injecting silicone might help, but there are many other factors to take into account.

6. Have you carefully inspected for an existing DPC - slate, bitumen etc.?





7. Have you researched your issues on here? In 2013 alone there have been a number of posts on precisely your issues.

Hi Dann

There has been a french drain along the two walls in question which I dug out about twelve months ago and then dug down to below the internal floor level in the hope that opening this up might solve the problem.
The channel is about 8 invhes wide and was left open, ie not back filled with stones to ensure maximum air flow.

My mate did most of the conversion and whilst I haven't yet stripped back the plasterboard he assures me that the membrane came over the floor and up the walls by about 12 inches

The interior walls are all plasterboarded throughout the property with the boards screwed to battens. Between the battens there is about 25mm of celotex. this was all done about ten years ago during the conversion but only these two walls show a problem and the problem seemed to appear about 5/6 years ago and has steadily progressed. No plastering has occured throughout the property since it's original conversion.

The exterior of the building is bare brick.

I have checked for any other dpc but cannot see anything. The building was roiginally a dutch barn built about 200 hundred years ago so not really sure what, if anything would have been used back then.

Hope the above narrows it down a bit and many thanks for your interest.

 

[dann09]

Thank you for the reply.

You really will have to do some research on here into these issues ref. rising damp, penetrating damp and condensation, and damp on battened plaster board.
Make a check list and tick off the variables one by one.

If its in your interest, then pics of the exterior elevation, the interior damaged areas before opening up, and the wall after its been opened up, will help us to help you.

Sometimes these things can be easily cleared up, eg. point the brickwork, extra ventilation, re-grade the ground level etc. but there are often many other variables.

Perhaps you would care to read another post i'm putting up in the building forum this evening?