Desperate for help with a damp problem! (pretty long)

[Anonymous]

Hi all,
I am having a big damp problem with one of my sitting room walls i have tried everything to try and sort it out but just as i thought i had solved the problem it jumped up and bit me on the @%*~.
it all started a couple of years ago when after i had decorated a few months later i noticed paint flaking off the wall, the wall seperates my sitting room from my staircase which is above my coal house (which is no longer a coal house) so the wall that i am having problems with is my coal house wall, with me so far? with it being an interior wall as such it is only a single brick wall meaning their is no cavity so all that seperates my coal house from my sitting room is a single brick wall. i thought that the problem was being caused by cold air condensing on the coal house side and seeping through the mortar joints and thus causing damp in the sitting room side because the flaking paint seem to follow the line of the stairs and if you go in the coal house and touch the wall you can feel that the wall is quite warmer because of the sitting room being warm. So what i decided to do was paint the wall in the coal house with bitumen paint put on some viscreen then polistyrene insulation sheets roughly 1 inch thick then lats and then marine ply to form some sort of insulated cavity to trap warm air and prevent the condensation. so about a month ago i painted on the bitumen and secured the sheet of viscreen with some pressure treated lats ready to put the ply on but today when i went to finish the job i noticed that all along the bottom their was a lot of condensation formed on the plastic sheet so i proceeded to lift up the excess plastic and the floor was saturated so i am now thinking that it is coming up from the floor as when i removed the plastic sheet the wall was bone dry. Please help!

 

[DaveL]

Derek,

Does the coal house have a damp proof membrane in the floor and in external walls? It may have been added to the house as a quick job to just keep the coal dry! This is a bit hard to fix, but it is possible. The other thing to check is for pipe runs, water or drains that are in the floor slab. A cracked pipe could be the cause.

Sorry no quick answers, just things to check.

 

[RogerS]

Derek

Two issues here, I think.

The first is the easy one....your last comment re water under the plastic sheet. I think that this is simply down to water being drawn out of the wall and condensing underneath the plastic sheet. It's why you always take a plastic mac with you into the desert. Dig a hole in the sand, put a tin can in the bottom, drape the plastic mac over the hole, water condenses and drips into the can.

Sorry, I digress.

Damp...usually comes in four ways...IIRC

1) rising damp.....most likely your cause

2) water penetration ..as in poor rendering and driving rain..prob. not the case with you

3) condensation from cooking etc on a colder wall...maybe

4) as already mentioned, leaky pipe

Regardless of which one (1-3) easiest option is to dryline the internal wall, redecorate and forget about it. If (4) then fix it!

Putting synthaprufe on your coal side of the wall is the worst option IMHO since any water being drawn up (rising damp) now cannot go into the coal cellar but into your room. Also, water will migrate towards the heat
...ergo...drylining.

 

[Anonymous]

Originally i thought rising damp but their is no where for the damp to come from as their is a void of about 1ft - 1.5ft beneath my sitting room which finishes at the wall where i am having the problems yes i do have a damp proof membrane on the outside of the house and in january i hired a dpc machine but it would not inject into the bricks as they are engineering bricks and are to hard. i really am at my wits end one thing i did notice that on my coal house floor their are what looks like wet patches at first i thought they where coal dust left over but after closeer inspection they are definately wet or damp patches coming through the concrete floor.

 

[RogerS]

Derek

Is the problem wall an inside wall?

yes i do have a damp proof membrane on the outside of the house - how do you mean 'on the outside of the house'? vertically? what sort is it? dpc's can fail. Sounds like you have, like me, an old house and which was never built on any form of dpc. C'est la vie. Part of the joys of living in an old house.

It still sounds to me that you have rising damp coming up the internal wall between your coal cellar and sitting room.

 

[Guest]

I too have a problem with damp on an inside wall but have traced it to a small leak in some flashing on the roof.It had been slowly trickling down the inside of the bricks until it eventually came out through the plaster. The plaster is in an awful state.

 

[Anonymous]

What i will do is try and post some photos to better explain my problem thats if i can figure out how to do it.

 

[Charley]

What i will do is try and post some photos to better explain my problem thats if i can figure out how to do it.

Derek, if you email me the photos, I'll upload them for you if you want.

 

[RogerS]

Derek

Check out this link https://www.energyefficiency.powergen.co.uk/advicecentre/category5/Dampness.htm

 

[Anonymous]

Charley i have sent you the photos and once again thanks.

 

[Jake]

Rising damp is actually very rare, it doesn't rise that far, and it won't rise through engineering bricks (which form a DPC by themselves). It is much more likely to be condensation. On which side of the plastic was the water?

 

[Anonymous]

It is much more likely to be condensation. On which side of the plastic was the water?

It was on the side facing the wall.

 

[Anonymous]

Here is the photos:

This photo shows the coal house wall painted with bitumen and the lats are in place ready for the ply.

This photo shows the damp patches on the floor which were left after i removed the plastic sheet which at first was saturated but have dried out a bit over night.

This photo shows more damp patches on the floor which were already their.

This photo shows the other side of that coal house wall after i had scraped off the loose paint sanded the wall and filled in the wall with pollyfilla but what happens is the paint follows the shape of the stairs so at the left hand side of the photo it starts out at a point then gradually opens up to about 2 foot then levels off all the way upto the door.

Hope this makes it clearer.

 

[RogerS]

Derek

Is the coal wall made of ordinary bricks or engineering bricks?

The slope on the wall in the coal hole picture...why is that? What's on the other side?

Hallway picture shows a red coloured floor? What is the floor made of?

Hallway wall...is the same as the black wall seen in your coal hole picture...but the hallway floor is about 2 ft up the coal hole wall?

Water on floor...could this simply have been caused by excess condensation underneath the plastic sheet?

What sources of moisture are there in the coalhole that can cause condensation (given that in an earlier post you said that you could feel this wall was warmer to the touch)

Have you tried a damp meter on your wall? You can get cheapy ones.

I am beginning to wonder whether your problem was simply salts leaching out of the wall but hard to say without a damp reading to confirm one way or another.

BTW how's the Ryobi router table?

 

[RogerS]

Derek

I think I may have the answer after a little research. I am quoting from Bench Joinery by Peter Brett.

"In addition to this surface condensation, there is another condesnation problem that occurs when wall surfaces are warm (ie your hall). This is known as interstitial or internal condesntaion. It is caused by warm moist air passing into the permeable structure until it cools, at which point it condenses thus leading to the same problems associated with penetrated and rising dampness. sound familiar

It can be dealt with either by the use of a vapour barrier on the WARM inside of the wall eg polythene sheet or foil backed plasterboard or

by allowing this water vapour to pass through the structure into a cavity where it can be dispersed by ventilation (I guess he means a cavity wall)

I'd still eliminate rising damp.

 

[Adam]

Derek,

A quick search throws up this result

https://www.ukworkshop.co.uk/forums/viewtopic.php?t=3679

From what I remember from rec.d-i-y it seems in almost every case, people need to dig a trench a foot or two deep around the foundations and back fill with gravel.

Anyway, if you click on the links I posted in the thread above, it should all become clear.

Adam

 

[Anonymous]

Roger the slope on the coal house wall is my staircase and the router table is pretty good as a starter kit to launch you into the world of routing.
I agree with you i don't think its rising damp either i am inclined to think condensation and the damp patches on the floor where not all caused by the plastic sheet if you look closely at the photo titled more damp patches you will see a line where the excess sheet was left on the floor.

 

[Anonymous]

Derek,

A quick search throws up this result

https://www.ukworkshop.co.uk/forums/viewtopic.php?t=3679

From what I remember from rec.d-i-y it seems in almost every case, people need to dig a trench a foot or two deep around the foundations and back fill with gravel.

Anyway, if you click on the links I posted in the thread above, it should all become clear.

Adam

The problem i have with that solution adam is that my coal house is underneath my stairs so in reality it is within the house if you see what i mean.