Rob_Impreza99

iTrader: (3)

Before we moved into the current house someone at some point has put in a full damp course in a room that i'm renovating at the min, its strange why its been done as the room has a cavity wall. A surveyor that came round in the past to check something else out said that it was probably done when it didn't need doing, he said certain companies would come out and give free quotes to people and then tell them that they need a full damp course.

Anyway on to my point, i want to dry line all the walls in plasterboard but the 1 metre area of grey plaster on the bottom of the walls is at least 2 inches thick and i want to knock it off so that the plaster boards can go on.

Ive read you can buy a paint on product that is a damp course, this would be ideal.

I mainly need to know is it ok to knock off the grey damp course thats on at the min seeing as we have a cavity wall and if so whats the name of the paint on product ?

mamoon2

Rob,

Have a look here, lots of useful info. - http://www.diydoctor.org.uk

I'm currently in the process of buying an edwardian house and have read lots of tips on there

Coffin Dodger

How old is the house? Just because it has cavity walls doesn't necessarily mean there is a damp proof course in place or that it hasn't failed. Can you not stud out the walls so that the plasterboard will sit more or less flush with the bottom layer?

speedking

DPC is a horizontal layer that separates the brick above from the bricks in contact with the ground to prevent rising damp. Usually 150mm above ground level.

Cavity walls do need damp proof course. Not really sure what you're describing? 2" thick plaster on inside face of room?

There is waterproof paint, but you must be sure there is no water pressure behind that will blow it off the surface.

Rob_Impreza99

iTrader: (3)

It already has a damp proof course in the room, the bricks along the bottom have the round holes where it was injected then this lumpy grey plaster went over the top. I'd say its 2 inches thick.

Here is a pic, if i leave that grey plaster on you wouldn't get boards over the top as its too thick, the architrave wouldn't go on as everyting would come out miles too far.

Theirs is virtually no gap between the far wall and the acrchitrave when its on, boards wouldn't fit unless that grey plaster comes off hence my question can it be knocked o0ff and replaced with a paint product.

andy97

iTrader: (1)

Look up Peter ***. They are one of the most respected timber and damp course specialists in the country. They use a chemical injection system into the brickwork. I have used them several times. on different houses

Andy

mamoon2

What has that got to do with his plastering dilemma?

john_s

iTrader: (1)

The new grey plaster isn't part of the DPC. It is usual to knock off and re-plaster the bottom metre or so of walls when installing chemical DPC, as salts carried into in the wall by the rising damp affect the plaster. The new plaster will be resistant to the salts that are still in the wall.

To me, it looks like the remedial DPC has been installed correctly (though it's impossible to say if it was necessary to be done).

From those pics, the renewed plastering doesn't look 2 inches thick - but without close ups, you can't really tell from the pics. Half an inch would be more like what you'd expect - though it may be thicker in places if needed to straighten the wall up.

The problem with using a paint product to replace the plaster could be that the paint will likely not be breathable, whereas the plaster will allow water vapour to pass. If the wall can't breathe, you might have damp problems again in the future.

My first thoughts would be to dry line the walls, keeping the boards as tight as possible over the new plaster and just use adhesive to hold it off the brickwork above. If the plaster is too thick that you can't dot & dab plasterboard over, then you might need to consider battening the tops of the walls out as mentioned above.

WRT the architrave - take it off , trim it down, and re-fit it once the plastering is finished.

DCI Gene Hunt

There is no such things as rising damp.

mamoon2

Then why are modern houses fitted with dpc?

Moisture can rise by capillary action

speedking

Wikipedia begs to differ

stevebt

iTrader: (8)

I beg to differ


http://www.youtube.com/watch?v=B0YOaH5n2x0

andy97

iTrader: (1)

That will teach me to read the heading and the replies

Rob_Impreza99

iTrader: (3)

john_s

Thanks for your detailed reply mate, ive got a surveyor/engineer nipping round tomorow to advise me. I'm hoping he will say that its ok to leave the grey plaster on the window wall which is exposed to the eliments then knock it of the other 3 walls.

Its 2 half cm thick, not 2 half inches ... I was having a bit of a blonde day yesterday, i aint even blonde either.

Coffin Dodger

Actually looking at the pictures (can't normally see them at work but the blocking software seems to have failed ) I'd say you'd be fine to clean all that grey render / plaster off and go back to brick. Then dot and dab plasterboard over it leaving the bottom brick (and the holes exposed) finally fit a skirting board suitably deep to close the gap.

I very much doubt you will have any damp problems.

I hope you are going to open up that fireplace in picture three, it would make a nice feature and is a crying shame that it's currently bricked up. Just make sure the chimney gets capped off if you not planning to use it as an actual fireplace

stevebt

iTrader: (8)

Even if he boards overt the walls he can open up the fireplace at a later date, I bought a cast iron fire surround from ebay and it looks superb even if its not a working fireplace

Rob_Impreza99

iTrader: (3)

It would make a nice feature alright lol, not the kind of feature i was after tho. The brick work is awful, if it had been nice bricks and render i would have opened it up.

I was toying with the idea of getting it re-built in something like a yorkshire brick type stone, ive no idea of the cost though to re-build a chimney breast in a nice stone brick.

PaulC72

NOt read the entire post, but iirc RIW do a paint on DPC which is especially good in places like basements etc so would I imagine work on any wall.

the other thing to bear in mind that damproofing is only a way to help stop a problem, the ideal way would be to try and eliminate that problem in the first place.