Plastering damaged plasterboard?

Discussion in 'Builders' Talk' started by iceboy, Feb 13, 2015.

  1. iceboy

    iceboy New Member

    Hi everyone
    I am in the process of renovating the flat. I had problems with possible asbestos etc but all seems okish at the moment and tests will be carried out before i can proceed with the plastering.

    I was wondering if you could guide me on how to plaster the damaged plasterboards. I am short of money and i would like to carry out the renovation myself.

    What is the cheapest and easist way to plaster or skim the plasterboard? I am not sure of the difference between plastering and skimming but i am guessing skimming is a thin layer of plaster which might just do the trick.

    Some sections damaged pretty deeper then other section so i need to make sure walls are plastered equally on same level.

    I would be gratefull if anyone could shed some light on the matter and guide me on the right direction.

    Thank you.
  2. Jitender

    Jitender Screwfix Select

    How much of an area have you do do, if its more than one wall then its worthwhile getting a plasterer in to give a quote.

    If you have never done plastering it will be difficult to achieve a good finish, from experience. Yes it will be expensive, but you wont be spending hours trying to sands bits down and filling in bits.
  3. Iceboy, are you really up for doing this yourself? If so, cooool.

    There are pros and cons with filling the hollows first and then skimming it all, or chust going for it. I think, on balance, 'going for it' will be best :).

    You could always do the former - mix up a small amount of skim and use it to fill all the damaged parts, and level off roughly using your trowel and the surrounding areas as your guide. You'll then have an even level surface to skim over afterwards.

    But the potential drawback with this is that you'll then have differently absorbing surfaces you'll be skimming on to, and you'll find that the filled bits will suck the water out of your skim so that when you run your trowel over it it's likely to be crumbly and drag lumps into the surrounding soft skim. You could, of course, counter that by brushing some water on to the dry filler first, and this should work, but you are as likely to now get these parts too wet and the opposite problem could occur...

    A pro plasterer will overcome such snags as they happen, but it ain't much fun for a novice :oops:

    So, you could then even try PVAing the whole wall to 'even it out', but - hey - you really wanna go there?

    So, considering that proper skimming involves applying two thin coats of skim, the second going on when the first is starting to 'go off', I'd be inclined to just 'go for it'; apply the first skim as you would normally, the only difference being that there will be some deeper areas to fill here and there. These areas should fill nicely and the skim should adhere to the old exposed plaster without any great issues.

    Level off this first coat as you would normally, and it should hopefully all look the same (that's a 'rough' level-off - don't worry about light tram lines and stuff.)

    Then apply your second coat - with the first coat now quite 'firm', I don't think you'll have any problems.

    To answer your basic Q - 'plastering' is just a general term and could apply to a whole bare brick wall being done with a thick 'bonding' coat followed by a finishing skim, or just to a skim coat being done. 'Skimming' is just the latter - the final finish coat around 3mm thick - the skimming plaster is often called 'thistle' presumably from a brand name.
    iceboy likes this.
  4. Yes thistle comes from thistle multi finish which is the most commonly used product
  5. If the damage is deep, pva then bond it out level.
    You haven't said if its new or old board, or previously skimmed.

    Whichever, Febond Blue-Grit the whole wall day before, include bonding out, then 2 coat multi finish.
  6. Use some thistle bonding coat to fill in the damaged areas, cut out any loose stuff first, make sure you fill it flat to the board, then your good to skim, but dont forget to pva the bonded areas first or the plaster will peel off when you paint
    Last edited by a moderator: Feb 16, 2015
    iceboy likes this.
  7. iceboy

    iceboy New Member

    Hi all,

    I have finally started plastering today after all the wall and furniture sanding and cleaning, it was time to get on with it.

    I bought the "Thistle all in one coat plaster".
    Done a trial today and will see how it is tomorrow.

    Can you put your valuable inputs on the state? Am i on the right direction? I will go over again tomorrow and sand it down for a smooth finish.

    20150221_181051~2.jpg 20150221_184204~2.jpg
  8. Looks fair enough in the pics, but obviously very hard for us to really tell.

    Are you planning to skim the whole wall now, or just the damaged areas like you've done? Are the rest of the walls good enough to paint?

    Anyways, you'll see what it's like tomoz when it dries. If you hold a lamp close to the wall surface either side, you'll soon see any hollows or high spots :).

    All you can do it sand and/or fill.

    Don't forget you can always resort to lining paper if needed. There is even a thicker stuff which will both cover larger issues and provide a good level of additional insulation. Forgot what it's called, but it's been mentioned on a 'insulating roof conservatory' thread.
    iceboy and FatHands like this.
  9. iceboy

    iceboy New Member

    Hi guys,

    I know i said the next day but i have been going through a nightmare. I sanded down the walls. Boy, was it a challenging task? Some part were like cement and wouldnt sand down. I had to use a heavy belt sander. I think on some sections, i have done pretty thick layers.

    Its all finished yesterday and it does not look too good. I mean the walls are smooth but in no way paintable smooth. Tiny layers of old plaster will just show up through the paintband its gonna look terrible i am sure.

    So i listend to Advocate's advice and bought lining papers today. I washed down the walls so no dust on the walls.

    Planning to start putting them up tomorrow. But before i do i was wondering if anyone can tell me the best way around doing it.

    Should i first seal the walls with watered down wall paste. Wait 12 hours and then put up the papers? Or do i not need to seal the walls?

    I am planning to paste them vertically.
    But i am not aure about the corners. On the outside corners of the walls, do i overlap the papers or should i just fold a layer of paper and paste it on the corners?

    Sorry about the questions butbi am really frustrated and want to get it done so i can deal with the rest of the house.

    Thank you.
  10. The only way to get a suitable finish with plaster is to skim the whole lot, I'm afraid. That will involve a coat of Blue Grit (I think...) first to provide a good key. And then I'd suggest getting a plasterer in...

    It might not cost that much if it's all ready for doing. Worth getting a quote?

    Anyways, not sure how to do lining paper, but I think it's usually laid on horizontally?
  11. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    First thing I'd do now is give it a quick coat of watered down emulsion. You will seal it and show just how perfect(or imperfect) the plaster is.

    Mr. HandyAndy - Really
  12. joinerjohn1

    joinerjohn1 Screwfix Select

    If your going with lining paper, (and doing it vertically) measure the width of the paper, mark the wall top, middle and bottom, this measurement out from one corner. Plumb all three marks (yep one will be closer to the corner than the others (coz the corner won't be plumb) ) Use the nearest line as your guide to paste the first drop up. Continue across the wall. When you reach the next corner, measure from the last drop , into the corner (again measure top, middle and bottom) Take the greatest measurement and cut the next drop, lengthways at this measurement and paste it up. The part you have left can be stuck to the wall round the corner (again plumb a line down so you know this piece is plumb). Carry on , until the whole room is papered. Admire your work whilst relaxing with a nice cold beer. ;);)

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice