1930s Damp Where to Start

JimsMoneyPit · Post by **JimsMoneyPit** » Fri Jul 10, 2020 1:37 pm

Hi

I'd be grateful for some advice where to start on this. We've got a 1930's semi with bay window and in the front lounge a suspended floor. I think we've been getting some penetrating damp from some cracks and poor drainage runs outside the house which we intend to fix.

I can understand if there is damp near the outside walls where it has penetrated, but don't see why the damp would be so patchy across the whole floor, and near the interior of the house as shown in the pics.

I'm planning on wiping it all down with bleach, then sticking a de-humidifer in to clear it all up and then see if it returns. Is that sensible?

Also it strikes me as odd that there is cement pipe (I believe containing asbestos) coming down from the air bricks just in to the room - I wouldn't have thought that would help with good airflow.

Thank you so much for any advice anyone can give!

Jim

toolbox · Post by **toolbox** » Fri Jul 10, 2020 3:04 pm

Well it is below the DPC so will always be damp unless tanked. Yes chances are the pipe is asbestos cement and I suspect put there to help ventilate.
Through ventilation will help that is air bricks on opposite sides, don't know why they ran the pipes in so far though.

wes56 · Post by **wes56** » Fri Jul 10, 2020 5:41 pm

Are you talking about penetrating damp below the floor or above the floor
Would you post pics of the outside of the house esp the bay, and pics inside the bay at skirting level?
There seems to be a kind of compound spread over some of the sub-area soil? Maybe the idea was to attempt to stop any damp coming up from the soil?
Damp is coming up from the ground so lots of through ventilation is needed to prevent condensation. Heavy Condensation will eventually rot the woodwork.
Are the circular "openings" vent outlets?
Bleach and a de-humidifier are a waste of your time - through ventilation under all the house suspended floors might be the best way to go.

The soil pipe looks like an oil pipeline - why?

JimsMoneyPit · Post by **JimsMoneyPit** » Fri Jul 10, 2020 7:51 pm

Thanks for the replies!

I've attached a few more pics from outside. We've recently redecorated the inside of the bay so its all nice and clean - there were no signs of damp when we did it.

JimsMoneyPit · Post by **JimsMoneyPit** » Fri Jul 10, 2020 7:52 pm

toolbox wrote: ↑Fri Jul 10, 2020 3:04 pm Well it is below the DPC so will always be damp unless tanked. Yes chances are the pipe is asbestos cement and I suspect put there to help ventilate.
Through ventilation will help that is air bricks on opposite sides, don't know why they ran the pipes in so far though.

Is it fair to just accept that it's damp then? Am I potentially worried about nothing?

JimsMoneyPit · Post by **JimsMoneyPit** » Fri Jul 10, 2020 8:02 pm

wes56 wrote: ↑Fri Jul 10, 2020 5:41 pm Are you talking about penetrating damp below the floor or above the floor

Yes, the rainwater drains were recently overflowing, and the neighbouring soakway not working so i'm guessing its backing up and somehow penetrating the brick?

wes56 wrote: ↑Fri Jul 10, 2020 5:41 pm There seems to be a kind of compound spread over some of the sub-area soil? Maybe the idea was to attempt to stop any damp coming up from the soil?

Yes, its like a rough chalky concrete kind of coating. Do you often just see soil then?

wes56 wrote: ↑Fri Jul 10, 2020 5:41 pm Are the circular "openings" vent outlets?

Yes, I guess they go through the concrete floored room next door and then out the other side of the house.

wes56 wrote: ↑Fri Jul 10, 2020 5:41 pm Bleach and a de-humidifier are a waste of your time - through ventilation under all the house suspended floors might be the best way to go.

How long might it take for the mould to clear up then? Will the mould just disappear over time if i can encourage the air bricks to work more effectively

wes56 wrote: ↑Fri Jul 10, 2020 5:41 pm The soil pipe looks like an oil pipeline - why?

It's set in brick 'saddles' i guess for the correct drop as It crosses the house and goes out the other side for some reason. Not really sure why, it heads toward the joining neighbour so maybe that has something to do with it.

wes56 · Post by **wes56** » Sat Jul 11, 2020 9:38 am

Yes, you will always have damp coming up from the soil and penetrating the below ground walls. Backing up soakaways or gullies wont help, of course.
The ground cover looks more like self levelling compound than concrete. Mostly i've seen soil under suspended floors. Laying a membrane, a DPM, over the soil might help.
Doubt that mould will ever disappear but clean it up if you feel better about a "clean sheet" to go on with.

toolbox · Post by **toolbox** » Sat Jul 11, 2020 12:57 pm

I notice neither of the downpipes discharge directly onto the drains a couple of fittings to take the downpipe directly into the grids would reduce the amount of water splashing onto the slabs and wall.

toolbox · Post by **toolbox** » Sat Jul 11, 2020 1:00 pm

JimsMoneyPit wrote: ↑Fri Jul 10, 2020 7:52 pm
toolbox wrote: ↑Fri Jul 10, 2020 3:04 pm Well it is below the DPC so will always be damp unless tanked. Yes chances are the pipe is asbestos cement and I suspect put there to help ventilate.
Through ventilation will help that is air bricks on opposite sides, don't know why they ran the pipes in so far though.
Is it fair to just accept that it's damp then? Am I potentially worried about nothing?

Lots like it as long as there is no sign of rot/mould on the joists just keep ventilated.

JimsMoneyPit · Post by **JimsMoneyPit** » Sat Jul 11, 2020 3:26 pm

Thank you both very much for taking the time to reply. I appreciate your advice.

toolbox wrote: ↑Sat Jul 11, 2020 12:57 pm I notice neither of the downpipes discharge directly onto the drains a couple of fittings to take the downpipe directly into the grids would reduce the amount of water splashing onto the slabs and wall.

We did think this wouldn't be helping. It looks like water has washed out any mortar sand etc from around the drain, so will definitely get some fittings to direct the water better.

I do intend to try and clean it up....if only to be able to see if it returns really.

Thank you again!