Prepping old walls for paint

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David321

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#249166 29-Apr-2019 07:41

Hi all,

I have been looking at stripping the old wallpaper in my place so I can paint the walls, the thing is being an old place the internal walls are that fiberious plaster stuff, not jib, which is not suitable for painting.

I had a decorator around for a quote on the smallest area to get an idea of what it would cost to have the house done (the hall with about 10 square meters of wall). I was told after stripping the wallpaper there would need to be a base layer of bedding compund smeered over the walls, then it needs a coat of pigmented sealer, then a coat of finishing compund and finally a vacuum sand, the price to have this done to my hallway was about $1500, meaning getting the whole house done would cost a fortune.

That got me thinking having that done would cost about $15 per square meter based on that quote, but replacing the walls with jib (something I could do myself) would be cheaper as the price of jib at bunnings is about $7 per square meter. I know the joins would still have to be plasterd which is something I think I could do myself.

Does anyone reading this have experience in this area, would it be a better idea to remove the old walls and replace with jib as it would be cheaper and I could do it myself (saving the hourly rate of the decorator). Or would there be some more steps neccessary that I have missed out?

_David_

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#2227086 29-Apr-2019 07:49

I went through this around 13 years ago with a 1950's bungalow. In hindsight, I should have done what you are contemplating (remove and re-gib). My reasons why I should have done this;

- house wasn't insulated - so I could have done this at the time

- opportunity to change out some of the wiring more easily

- even with a professional doing the plastering, it still never looked as good as the "new walls"

- huge involvement of my time (doing the seal coat and then tidying up the plasterers work to a paint ready state)

The thing to be wary of, is that in old houses they sometimes used to use a square that wasn't square :-) ... you may need to pack out to get new gib to sit properly. Not sure how good your gibbing skills are but here's my experience - use liquid nails/adhesive to hold gib to wall, use screws not clouts, use the concave edge on the gib together to do your visible joins (bedding it in with tape).

Good luck!

blackjack17

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#2227087 29-Apr-2019 07:51

If you replace the gib you also have the option of insulation.

Replacing the gib will be a big plaster job rather than just a skim, It would be worth getting some quotes to get it stopped, I looked at doing it myself but the cost of getting it done vs the time it would have taken me wasn't worth it.

If you regib you will also need new skirting boards and scotia.

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tdgeek

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#2227088 29-Apr-2019 07:54

$150 per square not $15

I'd have thought strip wallpaper, sand to tidy that up. Do a skim coat (easy to do), light sand, and seal and paint.

Skim coat is load up the trowel, dump it on thick, then skim it all off with the trowel. It will leave behind a thin layer and fill in imperfections. The seal coat and two top coat will also help cover minor imperfections, if you went ahead and removed wallpaper,did repairs (dings, marks) then did these 3 coats.

Paul1977

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#2227795 30-Apr-2019 10:07

@David321 where about's in the country are you. If you're in Christchurch I can recommend a good plasterer.

We just had one of our lath and plaster bathroom walls fibre fused and skimmed, looks great.

If memory serves he only scraped off the lining paper that was loose as he said there wasn't much point in doing the stuff that was stuck down hard since he was putting the fiber fuse over it anyway.

We pigmented sealed and painted ourselves, and you'd never know it was lath and plaster under it.

It was a very small wall but was only a couple of hundred for the stripping, fiber fusing, and plastering. That was four visits from the plasterer (not sure how he made any money from it.)

Another option is (depending on how great the finish needs to be) is to put sealer on the wallpaper and just paint over it. This will never look as good as new gib or a professional skim coat though.

rphenix

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#2230728 4-May-2019 11:14

I would recommend the replacing the lining with gib option - its not that big of a deal and you can find some other funky things, rotten wood, poor electrical cables, gives you the option of getting a sparky in to add extra power points easily that kind of thing which a bungalo will be short of. I would do this so I could insulate all the walls alone.

rphenix

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#2230731 4-May-2019 11:28

doublek:

The thing to be wary of, is that in old houses they sometimes used to use a square that wasn't square :-) ... you may need to pack out to get new gib to sit properly. Not sure how good your gibbing skills are but here's my experience - use liquid nails/adhesive to hold gib to wall, use screws not clouts, use the concave edge on the gib together to do your visible joins (bedding it in with tape).

Good luck!

Recommend all that. You can get Gib glue (the stuff that comes out green is best as it bonds to everything metal wood all sorts) don't glue where you will put screws unless you want to see depressions in the gib wall in 2 years. Plastic spaces they use for window installation is cheap and also another option along with fox wedges if you need to fix the alignment of a wall that and simply nudging the wall itself if its bare on both sides with a large mallet.

I would recommend tradeset 90 for the initial tape embedding it sets hard using a chemical reaction rather than air drying and your less likely to have the tape bubble out on you later as you put more thin smooth layers on top. Winstone have very good guides showing all the things you should do so its worth spending a few nights reading all the guides before you start. I didn't use any internal trims just paper embedding tape for my corners but I've since helped someone renovate who used goldline corner trim it makes for perfect corners and makes the job a lot easier so I would use those in the future.

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scuwp

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#2230733 4-May-2019 11:33

I am also in the new Gib camp. Having tried to skim coat and seal old walls before it's and absolute p*ick of a job! Paint finish is really hard to get perfect. You could re-wallpaper?

You might have to review your cost estimates for Gib. You will need to add skirting and Scotia, possibly insulation and wiring. Unless you know what you are doing I would be getting a plasterer in, it looks easy, but it isn't.

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neb

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#2230962 4-May-2019 20:07

blackjack17:
If you replace the gib you also have the option of insulation.

And the option of discovering rot in the framing that then needs remediation.

Not saying it'll happen, but something to consider.

Amosnz

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#2230975 4-May-2019 21:26

I second adding extra allowances for replacing skirting and cornice/scotia.

I wouldn't plaster the joins, get someone into do it. They bang it out in half (at least) the time, and at a much higher quality level than DIY'ers can. A small area like a hallway can work out more expensive as they have to do several visits, but if you have multiple rooms organised they can sometimes do 1 coat on everything and by then the start is ready for the 2nd coat.

Also check out the doorways/ windows to see if there is an architrave attached to the frames/reveals that can be removed or not. I've done a bit of re-gibbing in our 80's house and it was originally done with grooved jambs which makes putting up new sheets that bit harder. I'd imagine with the scrim this won't be a problem.

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froob

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#2231027 5-May-2019 08:12

We relined a couple of bedrooms in our 1939 house last year, replacing fibrous plaster sheets. A few extra things to think about beyond the comments above:

* The size of our fibrous plaster sheets were different to the new (metric) sheets of gib. This meant that the builder had to put blocking in the walls to support joins and batten the ceiling. That can obviously add cost, and also means the ceiling height is slightly lower. The alternative would be to cut the gib to fit the existing framing, but then you lose the tapered edges of the sheets at joins.

* Fortunately the sheets were about the same thickness, which otherwise would have meant adjustment at window and door reveals.

* If you are going to insulate exterior walls, and there is no existing insulation, then strictly speaking that will require building consent. There is an exemption in place for Christchurch for low risk insulation/cladding combinations, and may be for other regions as well. Yell out if you are in Christchurch and I will find the link to the information.

* If you are relining large areas, and are getting consent anyway, then you could get the designer to do a bracing plan and improve the wind/earthquake resilience of your house. This just involves putting more screws on particular sheets of gib in a specific pattern. But, I believe it counts as structural work and would need to be carried out or supervised by a licensed building practitioner.

* Insurance companies these days are keen to know if your house has been relined. This could get you a discount on your insurance - check with your insurer. I assume this is because of better fire performance (and possibly also because of bracing as above) and repairability.

* Our ceilings and some walls had lead paint. This meant with the skim coat option, the plasterer would invariable have been spreading lead paint dust around the place. Particularly with kids in the house, that would obviously not be ideal.

* This is Geekzone, so obviously it needs to be mentioned that removing linings gives you the opportunity to do some serious data cabling, including ceiling to floor runs, etc. The same applies for electrical, as mentioned above. That would obviously end up with extra cost.

* With either option, you will need to think how to protect the floors - plaster dust makes a huge mess, as well as the painting.

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David321

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#2231347 6-May-2019 06:35

Rather than replacing the scotia and skirting I was thinking or running a multy tool along the top of the skirting and below the scotia to cut along, then wall could be removed while leaving those two things in place, then it would be a matter of securing the new jib and sealing the join between the new jib and old skirting and scotia.

But after reading everything here I think it could be a bit of a risk to take on as it may not go as smoothly as I suspect, and its one of those things that once you start you must finish.

_David_

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blackjack17

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#2231367 6-May-2019 08:22

David321:

Rather than replacing the scotia and skirting I was thinking or running a multy tool along the top of the skirting and below the scotia to cut along, then wall could be removed while leaving those two things in place, then it would be a matter of securing the new jib and sealing the join between the new jib and old skirting and scotia.

But after reading everything here I think it could be a bit of a risk to take on as it may not go as smoothly as I suspect, and its one of those things that once you start you must finish.

Would be cheaper to replace skirting and scotia. Plus it would look terrible.

Depending on the style of the house you could square stop and so do away with the need for scotia (looks way more modern).

If you replace the gib I highly recommend getting a stopper in, they work so much faster and to a better level than a non-pro can do.

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elbrownos

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#2339606 17-Oct-2019 09:54

I've also got fibrous plasterboard in my late 1950's house, currently wallpapered.

It currently looks horrendous and I'll be happy with making it look reasonable, so I'm not interested in getting tradesmen or re-gibbing.

The plasterboard is very smooth and shiny (under the wallpaper) so I don't think paint will stick.

I've got a friend in the UK who recently redecorated using wallpaper that is designed to be painted over. This sounds like a good option for me, does anyone know if this wallpaper is available here?

Bung

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#2339703 17-Oct-2019 12:22

Just a comment that there is nothing inherent about fibrous plaster that stops it being painted. You probably have a house full of plaster ceilings covered in paint. In some areas they skim coat even new gib so there isn't a difference between joints and paper across the surface.

k1wi

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#2339754 17-Oct-2019 13:32

I prepped and painted lathe and plaster walls throughout my 1920s 130sqm home, that had previously been wallpapered. I had never skim plastered before, so I started with the spare bedrooms and definitely got better and faster as I worked through towards the ‘presentation’ rooms. All up the cost was $200-$300 for the skim coating plaster, plus quite a bit of plastic sheeting for dust control and then 80-100 litres or so of paint. We lucked out with wallpaper that was super easy to remove.

Even the imperfections of early walls fit the character of an older house and I’ve seen many worse walls in other houses of that era.

It’s also satisfying as hell to look at them now.

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