small damp patch in living room. I have a plan, will it work

[yappyboy]

I own a home in the country, on a small hill and it gets battered from the weather from 3 angles. When the house was built, there was a change of the roof design from a hip roof to a gable one but the chimney was already built up. When building the gables, they where tied into the chimney using L ties. I know now that the chimney should have been took down and rebuilt but that was 15 years ago. In that time, ive been getting a small damp patch right where my chimney wall meets the ceiling.

TBH, it only comes in winter time when the weather is real bad and goes away again when we get a dry spell. I eventually papered over it and it has only started in last 6 months to show some signs of mould on the paper.

I have 2 options, one is to pull the chimney down and rebuild it with a cavity around it so i wont get these damp patches ever again or option 2, i have some old natural stone stored away in my shed that would build a lovely stone fireplace.

Seeing as my chimney wall is flat(chimney breast is outside), i was thinking of building this natural stone firplace that steps out like a chimney breast in the living room. I will then run a course of vertical DPC on both sides, where the stone meets my chimney wall. I was thinking maybe i could stick the DPC to the wall using some sort of waterproof sealent then tie the stone into the wall using small L brackets with masonry nails that has rubber washers.

I know really that i should pull the chimney down but seeing as its a massive job and wil probably cost thousands that i dont have, i can only choose option 2 for now.

Im wondering would it be ok to use the brick/block DPC verticaly like i mention or would there be a better product on the market.

 

[conny]

Would it not be cheaper, and probably easier, to cure the penetrating damp from the outside? There are numerous products on the market so bound to be something suitable for your needs.

 

[yappyboy]

Would it not be cheaper, and probably easier, to cure the penetrating damp from the outside? There are numerous products on the market so bound to be something suitable for your needs.

I painted on ronseal weatherproof but it seems to still let th edamp through somehow. What other products would be out there. Someone mentioned tanking the inside but TBH, i know nothing about tanking a wall

 

[ree]

Your option 2 wont work as a remedial solution, its irrelevant to the problem(s) you describe.

If you post photos of the exterior and the interior it would really help.

 

[yappyboy]

Your option 2 wont work as a remedial solution, its irrelevant to the problem(s) you describe.

If you post photos of the exterior and the interior it would really help.

Yeah i know its not going to take the damp patch away but it will hide it away. To be fair, its only about 8inch radius patch and it goes away when the weather changes so i think it would be best to just hide it away for a few years instead of pulling the chimney down now when i dont have the funds to do so.

 

[Flyboytim]

It seems like you are describing condensation on a cold thermal bridge - winter only, disappearing in dry weather, not summer, and apparently returning even after dampseal treatment.

If there is a leak, it would be apparent when it rains, summer or winter, so installation of a dpc is unlikely to improve the situation.

Increasing air movement and changes of air together with avoidance of intermittent heating will keep the wall/ceiling junction above the dew point, and stop condensation, and prevent the growth of mould. For air movement, a desk fan is fine - it will mix the air and bring the wall and ceiling to the same temperature, removing the temperature differential that is needed for condensation to form.

If it is a holiday home, only occasionally occupied during the winter, it is important to have plenty of air movement when warming up cold rooms, else warm air will meet cold walls etc.

Have a look into the integrity of any thermal insulation in the immediate area on the other side of the damp patch, if possible. If there is a void in the area which is inaccessible, is it possible to wait till summer, when all is dry, and then use a can of polyurethane expanding foam to inject foam into the void through drilled holes that fit the foam applicator tube nozzle.

Mould can be removed with proprietary remedies, but I prefer the cheaper alternative of just using a synthetic bristle paintbrush to paint neat thick bleach over the mould, without any attempt to clean the mould before, and not scrubbing when laying the bleach over the mouldy patch. Leave to dry, and do not wipe off, preferably with ventilation and air movement. This should not damage painted or papered surfaces, beyond any damage already sustained from the dampness or mould.

The bleach will cause the mould to break down and disappear in a few minutes. If the mould stain is still there a little more bleach may be applied before the area dries off.

Once the area is properly dry and mould free, the area can be wiped with a damp cloth to remove any surface traces of bleach or any fibrous matter, from the dead mould.