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Damp Proofing

Dot and dab plastering in cellar

I live in a terraced house and I want to plaster the cellar, the back cellar was plastered a no of years ago, it was done by using a visqueen sheet stuck to a wooden frame which was plastered, Ive not had any issues except that theres a slight smell in the morning.

I dont really have any damp issues in the front cellar except that cardboard boxes go a bit soft after being left there for a while, the walls are dry. I have beed advised that using dot and dab with a damp proof plasterboard will do the trick, and theres no need to baton the whole room with a wooden frame.
can anyone please advise?
I have been told If I use a wooden fram then eventually the damp will cause the frame to rot. I was wondering is the waterproof membrane stuck to the wall and then th batons fitted on top therefore no damp will get to the timber?

10 Answers from MyBuilder Damp Proofing Specialists

Best Answer

If your cellar has a musty damp smell the question is why? Either you are suffering from lateral penetrating damp if all walls are earth retaining and in this instance you will see signs in the mortar and brickwork or is your slab/screed of good structure and sound of any defects to help aid rising damp through it? Does it have a Membrane and screed over the top or just a shallow slab onto a clay or soil base?
Ventilation would be a plus if you can incorporate a method of maybe a basic vent or a heat recovery system to exchange the musty damp cold air and bring in clean and warm air.
Personally if you are getting any amount of moisture you never dot n dab and timber is a no no on damp walls! Galvernised Tracking systems are a good idea but i would opt for a Cavity Drainage membrane system either with or without a pump and i imagine in your situation the pump isnt paramount.
The Membrane encapsulates the area fixed to the walls and floors and after being taped and drilled/plugged it will stand and keep your property dry and safe for storage...Its not cheap but it is 100% moisture resistant.
If you would like to look at diagrams of Membrane systems look to Delta or John Newton as they are suppliers of these systems.

Nearly forgot to add,you can fix timber battens to the membrane by meens of the plugs as they have threads to enable screws to be inserted or put up your Galvernised tracking and then board it out.

I hope some of the information helps and good luck,heres hoping for a dry and damp free Cellar for you.

Scott Cannon
Cannon Preservation.


Answered 15th May 2011

If you mean foil-backed board (Duplex),then yes you can perhaps use these but who advised you to dot & dab them?
(Expert advice from a 'plasterer' i guess;)

If anyone dot & dabs foil-backed boards onto brickwork,you will find them on the floor the next will have to baton the walls first with timber & screw the boards on.

If the walls are dry and you have no issues with damp,but
you want to play it safe,i would personally baton walls out first then use Celotex,Kingspan between batons then normal 12.5mm plasterboard.
That way,you kill 2 birds with 1 stone.............control vapour/damp & provide insulation at the same time.
Particularly good if you intend to use it as a proper room.

If it's just a tidy up job,then yes use 12.5mm Duplex but make sure they are fixed onto timber batons.


I agree AJ...........
some shocking advice from so called 'professionals' on here.

By the way,anyone know where i can buy foil-backed moisture resistant plasterboards from.................? ;)



if you use waterproof membrane first then fix batons,then yes it will stop the damp from getting through to the timber but you've said you have no real issues with damp and the walls are dry.
Which is it?
My answer and advice is based on that.


Answered 18th May 2011

I would not use the method that you have discribed below ground? if ever there was some damp in an area it would come thru the board in no time from the wall? penatrating damp. I think the best option for you is to metal stud the walls making a frame and fixing it just a few centermeters off the walls, insulating between the walls and P/boards and tuck some behind the metal stud, then fixing moisture resistant boards to the metal studding leaving a small gap at the bottom so the Board is not touching the floor then finish as required. make sure you have ventilation in the celler also as this is why you have the smell? it needs to be ventilated also so you dont get any mould or rot issues down there? that could be devastating. hope this helps a bit and gives you another option...


Answered 8th May 2011

dw plastering should know better - you cannot dot and dab foil backed plasterboard!


Answered 9th May 2011

A waterproof render will stop the moisture.
If it is only very slight then better ventilation should fix it.


Answered 8th May 2011

Hi , I think the best way would to be to employ a recognised damp specialist and basement conversion company to take a look and give you a detailed report with cause and remedy , If the boxes are going soft but you feel there is no damp its a humidity problem , most basements can soon become dry if ventilated correctly . Also I would advise not using plasterboard but a water resistant plasterable panel (any good builders suppliers will have information ) this will eliminate any penetrative damp issues.
Nigel - dampuk
Absolute Building Force


Answered 18th May 2011

Having received an email today i have found out some joker got into my account and answered a question with a laughtable answer and made me look a right prat so thanks to whoever did this and thanks to the other builders on here who jumped on me.

So ive been asked by mybuilder to reply with a proper solution,
First of all if you have damp and it smells you need to get some form of ventilation in your cellar, also if you are thinking of boarding the walls and NOT dot and dab any damp will eventually come through in time, your best bet to guarantee damp stays away is to use a waterproof render with sika or something similar and that should do the trick.


Answered 18th May 2011

I would not advice dot and dab in a cellar. You may not be able to see the damp but it may be there as plasterboard adhesive is quite absorbent it will atract damp to it then it could fall off . Platon membrane then battens woukd be a better alternative


Answered 8th May 2011

You cannot dot & dab foil backed plasterboard, it will fall of, maybe just after the builders cheque has cleared.
Sounds like the original system you have is ok, batten walls, insulate between, and boards screwed to battens.


Answered 9th May 2011

hi take off visqueen replace with breather membrane board and skim should have no problems !!!


Answered 17th May 2011

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