Damp Proofing

[JustBen]

Hello Guys,

I have recently moved into a house that has some damp in the main reception room. Mostly at either end in the corners on one wall.
I had someone come and look who advised where the damp was and he said he was going to tank the walls with some black liquid which will form the damp proofing
he was planning on going 1 meter up right down the wall.

I feel its something with a little help i could likely to myself which should save me a good chunk of money.

my partners dad has used a chemical mixture from soverign chemicals which he applied with a paint brush before and said this worked well for him.

I've looked online and there's a few choices on what to use. first choice is to use plastic membrane or go down the liquid slurry type mixes.
Has anyone used the membrane? Is it as good as it makes out and do you have to go from floor to ceiling or just the 1meter up you tend to go with normal tanking?

With the slurry mixes is one better than the other? any recommendations?

Going to take the carpet up tonight and move it to a spare room as it'll be a nightmare keeping clean. Then mark out the wall for bringing the plaster off.

I'm in a good position that i am not living in the house and have a deadline of middle of september to get in so can take m time doing it

 

[JustBen]

cheers guys,
when the 2nd company came around to give me their opinion i was there so could see what they did to come to their conclusion. they had a damp meter which they just pressed against the wall in various places. The bit in the corner is next to a door which read quite high on the damp meter. then it tailed off into the middle of the room which a reading of around 10 which they said is fine then it went up into the 20s near the front of the house. their thought was to knock the walls back where the damp was registered and then do the bit between the two main damp spots.

Prior to getting the house a 'damp report' was done which was fairly vague much to my displeasure which said a new damp proof course is required but that was it.

One of the gutters is leaking at the front of the house but in an opposite corner(getting this fixed tomorrow) and i know the chimney stack is leaking but that's on the inner walls only causing 2 bedroom walls to become damp not the ones affected downstairs (this is also being resolved tomorrow)

The house is quite warm and seems to be well insulated, we looked around this house around February so when it was colder and it was warm in the house despite the heating being off and no one living in it.

I forgot to mention and i'm not sure its relevant but the house was all pebble dashed in the last 2 years. I have checked and the air brick at the front of the house looks to be ok, its not clogged up.

The damp appears to be only near the floor.

Trickle vents i'll look into as the house is quite warm.

*edit - exact wording of report*
' high reading of damp to all walls within the main reception only. these are now require treating by installing a new damp proof course
all skirting boards on damp affected walls to be treated need replacing. all timbers that could be inspected were found to be adequate and clear of rot and infectation at time of inspection.
additional airbricks are also required to the front elevation after cavities have been cleared'

 

[JustBen]

i'll grab some air bricks tonight from screwfix if they have them and fit them on Friday, reading online you should have them every 6' i have one on the front of the house and haven't noticed one on the back. Fitting the air brick would also give me opertunity to try checking the cavity wall for rubbish.

If Something like this was the cause of the damp how would i know? Do you need to leave it x amount of days and then check with a damp meter again?

 

[JustBen]

It could be.
Fitting air bricks is a good idea, but if you have a cavity you will need a duct to go from the brick to the underside of the floor and above that you will need a DPC mortared in to the inner leaf with weep vents to discharge any water.

The DPC should be 150mm above finished external ground level, air bricks are usually at least 75mm above the ground. That's all for new builds so if your house is old there may have to be some adjustment, a decent builder will be able to advise, it may mean you have them lower.

You should also have a dwarf wall supporting the floor (assuming its hollow timber, not pre-cast concrete) to allow flow of air.

The air bricks are really not very far of the ground. I've noticed i have two at the front and none at the back.

Can i use something like
http://www.manthorpe.co.uk/Building...Underfloor-Vents/Refurbishment-Weep-Vent.html at multiple points? Looks a bit to simple.

I've taken the skirting boards of tonight. some of the wall is rather damp!

 

[JustBen]

Ordered 4 trickle vents for the window and french doors. going to drill into the wall where the wallpaper was damp t see if it is actually wet.

 

[JustBen]

Well i spent all yesterday around the house...
First i took the plaster off around the skirtings to make a nice clean cut as it was crumbly after taking the old skirtings off. The plaster was dry
I then took the wall paper off and there was some black dots behind a couple of bits, the wall was a little wet on the surface but the wall paper was quite thick so suspect not breathable.
I drilled a few holes into the plaster where the damp was 'detected' and it was dry
So i'm happy i spent a few hours reading the link joelk2 provided as it's saved me a chunk of money. How the firms quote over a thousand when there's nothing wrong is beyond me.

oh and in preparation to making a mess bringing the carpet up i realized there's a very nice wooden floor which ive decided im keeping. The carpet from the room is going to be enough to carpet the two rooms upstairs that need new ones.

 

[JustBen]

glad it was of some use.

when we had areas of damp (on the building survey) the damp survey guy said most of our damp would have been caused by our wallpaper (thick wallpaper on every wall in the house)

we stripped everything (some room were wallpapered ceilings)

I think this was the cause for the mildue, reading up you can buy nonwoven wallpaper which is breathable so you wont' get mildue . Also looking into clay based paints from earthborne as they're breathable as well.

The money saved should mean i can afford an induction hobbed oven