How to prep wall for paint

Forums › Home Workshop DIY › How to prep wall for paint

David321

507 posts

Ultimate Geek
+1 received by user: 105

#268646 30-Mar-2020 14:51

Hi all,

I am currently looking to strip some wall paper in a bedroom in my house, I have pulled a little bit off already to see what is behind it and it looks to be bare gib. Usually I know most professional decorators will smear on a bedding compound, sand, skim coat, sand and then undercoat and top coat.

The problem with this is the price, I have had a couple of quotes on smaller areas to have walls prepared for painting using this process and confirm its far from cheap and its not something I would be to confident doing myself (have given it a lot of thought). So I am looking into other effective ways of getting this done myself without resorting to bedding compound and a skim coat.

I have done a bit of research and found something called "Resene Broadwall Surface Prep", it is described by Resene as a hybrid paint and plaster mix designed to improve wallboard finish. To me it looks ideal if I want to avoid bedding compound and skim coating, but I want to know if I am on to a good idea here and perhaps if anyone reading this has some experience or knowledge with this product, or perhaps another suggestion as to how I could tackle this job?

P:S I am are I will need to add sealer coat before top coats :)

Link to product description here: https://www.resene.co.nz/homeown/painting-your-home/Painting_Interior_Walls.pdf

_David_

1 | 2

3566 posts

Uber Geek
+1 received by user: 1519

Trusted

#2450100 30-Mar-2020 15:15

Broadwall surface prep is a good product, but your walls would have to be pretty janky to justify the time and expense (and minimum 4 week lockdown wait to buy something) to need it.

With proper prep, paint sticks pretty well to wallpaper. Personally I'd just be looking to paint what is already there. Or is it in too bad condition?

Bung

6733 posts

Uber Geek
+1 received by user: 2926

Subscriber

#2450150 30-Mar-2020 16:15

I doubt that many bedrooms would get skim coated. That is required for the top grade of finishing when you want gloss paints or have difficult lighting.

Amosnz

569 posts

Ultimate Geek
+1 received by user: 131

Lifetime subscriber

#2450152 30-Mar-2020 16:23

My wife is stripping the wallpaper from a bedroom as we speak, the last bedroom of the house done over many years.

I usually only give the gib a coat of plaster/sand on areas that need it (nail holes, where the top paper layer of the plasterboard has been torn up, joins, any visual defects that are easy to pickup. After a first undercoat more are always visible but after a 2nd touch-up round its always come up good. Our plaster is 80's and in reasonable condition.

I had friends that used the broadwall sealer on their walls because they were in terrible condition after taking the paper off, they said it worked well.

Speedtest

neb

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#2450160 30-Mar-2020 16:32

Just thinking out loud here but given the price of gib if you're going to that much effort and cost could it be cheaper to just strip the gib and everything on it out, drop in insulation while the walls are uncovered, and re-gib? Neighbour did that, working through room by room, and we're going to do it in rooms affected by the Casa de Cowboy rebuild.

SATTV

1670 posts

Uber Geek
+1 received by user: 657

ID Verified

#2450168 30-Mar-2020 16:54

neb: Just thinking out loud here but given the price of gib if you're going to that much effort and cost could it be cheaper to just strip the gib and everything on it out, drop in insulation while the walls are uncovered, and re-gib? Neighbour did that, working through room by room, and we're going to do it in rooms affected by the Casa de Cowboy rebuild.

We were talking about redoing the bedrooms next year, Ours is 1966 plaster and never designed for painting.

I am thinking of replacing all the gib and putting in insulation at the same time.

John

I know enough to be dangerous

David321

507 posts

Ultimate Geek
+1 received by user: 105

#2450170 30-Mar-2020 16:59

Cheers for all the info, some further information to provide based on peoples advice so far:

1- Not sure what condition the walls will be in after removing the paper, I will find out once the paper is off.

2- The paper is in to bad of a condition to paint over, this is not an option.

3- I don't mind spending a little extra on the broadwall prep if it will give me a much better finish. I get 25% off at Resene through my employer.

4- Does the broadwall prep need to be sanded? before applying pigmented sealer?

5- Not to keen on re-gibing as that is a bit of a major compared to slapping on a few coats of paint.

This is something I will undertake once the lockdown is over as I have no products I need yet.

I am thinking this - Strip paper, spotfix any holes/damage with putty, apply broadwall prep, (sand if required?), apply Resene Sureseal pigmented sealer, apply two top coats of Resene Low Sheen top coat.

Sound like the way to go? I have heard you can apply two coats of the broadwall sealer if the walls are in terrible condition, but I do not think mine will be to bad. Is it necessary to sand the broadwall sealer? You have to use a "high solids" roller to apply it, maybe that roller provides a rough/textured finish to help hide imperfections?

_David_

Apple TV

Stream your favourite shows now on Apple TV (affiliate link).

hsvhel

1273 posts

Uber Geek
+1 received by user: 596

ID Verified

#2450171 30-Mar-2020 17:00

SATTV:

neb: Just thinking out loud here but given the price of gib if you're going to that much effort and cost could it be cheaper to just strip the gib and everything on it out, drop in insulation while the walls are uncovered, and re-gib? Neighbour did that, working through room by room, and we're going to do it in rooms affected by the Casa de Cowboy rebuild.

We were talking about redoing the bedrooms next year, Ours is 1966 plaster and never designed for painting.

I am thinking of replacing all the gib and putting in insulation at the same time.

John

Would be the perfect time to insulate.

We recently stripped the paper off and had the whole house plastered for paint......6 months on, there's still dust turning up!

Referral Link Quic

Free Setup use R502152EQH6OK on check out

David321

507 posts

Ultimate Geek
+1 received by user: 105

#2450176 30-Mar-2020 17:06

SATTV:

We were talking about redoing the bedrooms next year, Ours is 1966 plaster and never designed for painting.

I am thinking of replacing all the gib and putting in insulation at the same time.

John

Hi John, can you explain how your plaster is not suitable for painting? my house is a 1953 bungalow, I am assuming when I remove the paper in the other rooms I might find similar plasterboard, probably that fibreous plaster stuff.

As far as I am aware the Resene Broadwall Prep should bring even those old walls to a paintable finish? Do you not think it would work on your walls?

_David_

shanes

270 posts

Ultimate Geek
+1 received by user: 84

Lifetime subscriber

#2450179 30-Mar-2020 17:09

neb: could it be cheaper to just strip the gib and everything on it out, drop in insulation while the walls are uncovered, and re-gib?

It might pay to check with your council, I think some of them require building consent for insulating external walls.

Amosnz

569 posts

Ultimate Geek
+1 received by user: 131

Lifetime subscriber

#2450188 30-Mar-2020 17:21

neb: could it be cheaper to just strip the gib and everything on it out, drop in insulation while the walls are uncovered, and re-gib?

Our window frames, door frames, robe door frames all have grooved jambs which are a pain to get gib and have joins in the correct places (especially when a door is close to a wall end), if you have windows/doors with a separate surround this would be much easier.

Speedtest

mdf

3566 posts

Uber Geek
+1 received by user: 1519

Trusted

#2450193 30-Mar-2020 17:37

Broadwall is typically only needed if you want a level 5 finish (i.e. ultra smooth or unusual requirements). Level 4 is pretty much a perfect finish for "normal" rooms - see https://www.gib.co.nz/homeowners/achieving-a-quality-finish/. It is more designed to finish/ultrasmooth something that is already pretty good. It won't (easily) fill big holes or dents on its own.

If you are applying over old gib, you will need to seal with Sureseal first (stops tannin leaching), then broadwall, then (most likely) 2 top coats.

Unless you are applying it with a wand and wingardium leviosa spell, Broadwall will almost certainly require at least a light sand before topcoating. This is essentially what it is designed for.

If it were me and wallpaper required stripping (assuming bare gib underneath):

1. Spot fill holes and worst imperfections.

Selleys rapidfilla is good (the coloured one is awesome). Sand back overfill as required

2. Full wall light sand

3. Wash with sugarsoap and rinse

4. One coat Sureseal pigmented sealer. Yes you have to used the oilbased, and yes it is a smelly pain and will require a long time before overcoating, but you will regret not using it if you don't and your topcoats discolour because of tannin leaching.

5. One coat Quickdry acrylic primer undercoat

5A (optional). Find the spots you failed to fill properly the first time. Refill, resand and spot prime. Repeat as often as desired.

6. Two top coats Resene Spacecote low sheen / flat in the colour of your choice

Always do your cutting in first, then go back and roll the rest using a low nap roller and laying off vertically.

Apple TV

Stream your favourite shows now on Apple TV (affiliate link).

SATTV

1670 posts

Uber Geek
+1 received by user: 657

ID Verified

#2450208 30-Mar-2020 17:57

David321:

SATTV:

We were talking about redoing the bedrooms next year, Ours is 1966 plaster and never designed for painting.

I am thinking of replacing all the gib and putting in insulation at the same time.

John

Hi John, can you explain how your plaster is not suitable for painting? my house is a 1953 bungalow, I am assuming when I remove the paper in the other rooms I might find similar plasterboard, probably that fibreous plaster stuff.

As far as I am aware the Resene Broadwall Prep should bring even those old walls to a paintable finish? Do you not think it would work on your walls?

Back when our house was built the gib was a flat bit of board, there was no hollow for the tape and plaster so you get a plaster lump at every join, you dont get a nice flat finish that you need for paint.

You can plaster it, I tried and failed, I got a cheap plasterer in, he also tried and failed, I then paid for a proper job and got a proper result.

I have not used that roll on plaster, but I have heard it is OK, but I guess it depends on how good the builder / plaster was when the house was constructed.

John

I know enough to be dangerous

frankv

5705 posts

Uber Geek
+1 received by user: 3666

Lifetime subscriber

#2450209 30-Mar-2020 18:00

The real question that no one has asked is what you want to do afterwards. Do you want to paint the walls, or wallpaper? If you intend to paint, you probably need better preparation than for wallpaper. Depending how cheap the wallpaper is.

David321

507 posts

Ultimate Geek
+1 received by user: 105

#2450212 30-Mar-2020 18:03

mdf:

Broadwall is typically only needed if you want a level 5 finish (i.e. ultra smooth or unusual requirements). Level 4 is pretty much a perfect finish for "normal" rooms - see https://www.gib.co.nz/homeowners/achieving-a-quality-finish/. It is more designed to finish/ultrasmooth something that is already pretty good. It won't (easily) fill big holes or dents on its own.

If you are applying over old gib, you will need to seal with Sureseal first (stops tannin leaching), then broadwall, then (most likely) 2 top coats.

Unless you are applying it with a wand and wingardium leviosa spell, Broadwall will almost certainly require at least a light sand before topcoating. This is essentially what it is designed for.

If it were me and wallpaper required stripping (assuming bare gib underneath):

1. Spot fill holes and worst imperfections.

Selleys rapidfilla is good (the coloured one is awesome). Sand back overfill as required

2. Full wall light sand

3. Wash with sugarsoap and rinse

4. One coat Sureseal pigmented sealer. Yes you have to used the oilbased, and yes it is a smelly pain and will require a long time before overcoating, but you will regret not using it if you don't and your topcoats discolour because of tannin leaching.

5. One coat Quickdry acrylic primer undercoat

5A (optional). Find the spots you failed to fill properly the first time. Refill, resand and spot prime. Repeat as often as desired.

6. Two top coats Resene Spacecote low sheen / flat in the colour of your choice

Always do your cutting in first, then go back and roll the rest using a low nap roller and laying off vertically.

Sounds like you know your stuff! I did not realize an undercoat was required on top of the pigmented sealer before applying top coats, just assumed the top coats could go on to the pigmented sealer? no problem putting water based products on the oil based pigmented sealer?

_David_

mdf

3566 posts

Uber Geek
+1 received by user: 1519

Trusted

#2450230 30-Mar-2020 18:36

Quickdry is pretty amazing stuff and will cover up all manner of sins, both surface quality (within reason) and any patchiness in colour that you are overcoating. You don't strictly need it, but some colours/tints definitely conceal what's underneath better than others. Better IMHO just to do it properly with an undercoat than end up doing a third or fourth top coat to get the finish you want.

No worries about overcoating acrylic over oil, so long as the oil is _thoroughly_ dry. I've just checked the label online and it claims 3 hours but I usually aim for next day to make sure.

1 | 2