Damp Proofing

Damp in living room around the bay

Anonymous user 23/02/2024 - 3.01 PM

Hi, I have random damp patches which appears in rain and disappears on a dry day around my bay. The property is 1920's and I'm doing a little renovation to rent. i had the room plastered and i painted it with matt emulsion with no idea of damp being present. since painting it there are wet patches appearing with rain, almost instantly. the bay is about 3 foot high where it reaches the window sill. its a three wall bay and each wall are about 800mm long, on the one side i get a small circle about 30mm wide in the centre but dry around it, above the skirting i get a "wave mark" about 12" long and 2" high. the other wall i get another "wave mark" about 6 inches long and 2" high with the same on the 3rd wall. then the two walls that meet the bay seam to get large wet patches in the rain upto about 2 foot high. the widow sill was rotten in places so I've removed it currently and the upvc window has been fitted terribly, the sill leans back to the frame. I've siliconed where the frame meets the window to prevent water ingress. its a solid wall and the bricks below the sill look very damp and dark in places. I've had someone damp inject the wall last week but I'm not convinced this is the problem. I've sealed the bricks with thompsons out side and pointed any poor mortar joints. the airbricks are clear under the floor boards which are directly below and there nothing bridging the damp course externally, which appears to be slate. the inside I've drilled out some mortar where the dpm should be and theres slate but not everywhere, bits seam to be missing. would rising damp come and go so quickly with rain, the plaster looks soaked when rain comes. my feeling is it could be the window as it so suddenly appears with rain? the mortar is damp both low level and high level (by the window) the bay has a flat roof ontopwhich isn't leaking and gutters are ok. Any input is greatly appreciated. Cheers Chris