Damp Window and Door Reveals

[Joe Morris]

Hi All!

I hope someone might be able to advise me on an issue regarding dampness adjacent to the front window and front door in my house on the reveals.

There is a large overhang/soffit immediately outside these areas, where very little rainwater lands in the face of the brickwork outside. Nonetheless, I did some repointing, I've also checked the gutters, repointed the leadwork of the protrusion above the window, and resealed the perimeter of the window and door outside with uPVC beading and CT1. I don't see how it could be penetrating damp, but there's no denying that the issues get worse during long periods of heavy rain. I don't think it's rising damp either, as there is no evidence of moisture at lower levels, the worst is around shoulder/head height.

I have scraped the peeling paint back and found quite badly cracking plaster, which I hacked off and found a vertical DPC inset ~40mm inside the door frame (photo below). This is where the damp patch is, and naturally the DPC seems to stop the damp continuing further into the interior. Judging from the damp pattern on the plaster around the living room window, there is a vertical DPC inset from that frame aswell (photo below as well).

As I've exhausted most typical avenues outside (pointing/gutters/lead flashings), I am wondering if the brickwork is somehow attracting moisture from the air, as there has previously been salt deposits on the exterior brickwork that I've removed in the past. The vertical DPC's also seem to be doing their job, but shouldn't they be in-line with the windows/doors rather than inset from them?

Basically, if anybody has any ideas as to why this is happening and how to remedy this, it would be much appreciated.

Cheers

Joe

 

[KenGMac]

Joe Morris, good evening.

It is possible that the vertical DPC you have uncovered has been fitted incorrectly, in that the position of these DPCs is important as regards the door or window.

The DPC should be positioned so that the window [or door frame] outer corner is in line with. or sometimes touching the DPC, the internal reveal block travels past the window up to the DPC.

In your case, the DPC is positioned within the room, that is on the room side of the window.

Hope you are still with me?

if we consider where your DPC is in effect the "Damp / Wet" wall is encroaching past the window and into the room, hence the dampness.

Have a search for " vertical DPC at window reveals" lots of images on the WWW

Ken.

 

[Joe Morris]

Hi Ken, thanks very much for your reply. What you have said makes perfect sense, and yes indeed the DPC is encroaching past the window and into the room itself. Unfortunately I'm not going to be in a position to perform massive remedial works to rectify the position of the DPC, or replace the door and window. Is there a way I can try to resolve the issue without the need for major works to be done? Perhaps applying a waterproof coating to the exterior brickwork outside the window, and/or applying a damp proof layer on the "wet" side of the DPC, before making good?

Cheers

Joe

 

[KenGMac]

Joe, good evening again.

OK looks as if the actual detailing has not been best considered?

Where to go from here?

if it were me? This is a "fix" of sorts.
1/. Remove the plaster between the vertical DPC and the window, if possible between window and wall.
2/. Allow the wall to dry out use a fan or something to move the air past the exposed masonry / brickwork.
3/. Remove as much dust / debris from the wall as you can [Wire brush?]
4/. Find and apply something like "Bituthene Strip" this material is a very, very sticky flexible DPC membrane, there are several such "tape" flexible [specialist] DPCs
5/. Use a "tape" as above, you will have to get the width you need as below.
6/. Fit the tape as far into the gap between window and wall as possible, drape and get a contact with the wall up to and overlap as far as possible on to the existing DPC. This is possibly not an easy ask, the tape will stick where you don not want it to, it may not get "between wall and window, will wrinkle on the exposed wall, will be problematic in sticking to the existing vertical DPC, but you can cut off bits and because it is sticky, get as big a lap as possible and carry on. it will not look pretty, but you are going to cover it?

What the above [rant] is all about is to "extend" the existing vertical DPC so the reveal is dry.

Ken.

 

[Joe Morris]

Hey Ken,

Thank you very much for your advice, I will look your suggestion of using the bituthene strip. If not, I will look into some similar way of creating a waterproof layer between the window and DPC. Cheers, Joe