Painting/decorating advice needed

jackspade

New to DIY'ing,  attempted to paint strip a wall as it had bad peeling and flaking paint but turned into a mess. We have been scraping back to the bare wall but now have been told it will need PVA'ing and plastering as you cant paint onto a bare wall.   How hard is plastering?

The original goal was just to re-paint 3 walls, half a room.  What grit sandpaper do you use to sand previously painted walls ( silk ) to prepare them for new paint ( matt ) ?  80 or 120?  Do you need an undercoat after sanding?

I got a professional to quote for the job and he said 550 labour only, ( skim plaster 1 wall, paint 3 walls )

Any advice greatly appreciated

FreeBear

jackspade said: We have been scraping back to the bare wall but now have been told it will need PVA'ing and plastering as you cant paint onto a bare wall.   How hard is plastering?

To slap a bit of plaster on to a wall, not very difficult. To get a decent smooth finish ready to be painted takes a lot of experience and practice.

Although I can do small sections, for a wall or ceiling, it is well worth the £150-200 (plus materials) per day that a plasterer charges.

donemedosh

Plastering a whole wall is not easy & I have been doing Diy for years & plastering a wall is one of the hardest things to do & so many things could go wrong. I would try 1) Wash the wall down with sugarsoap & a scotchbrite pad then rinse with clean water let it dry. 2) Using electric sander sand wall with 80grit. (buy a roll of sandpaper if you use the sander pads it will cost you a fortune.) 3) paint wall using a roller & zinsser 123 it is a primer sealer that i think is the best on the market but it does cost about £20 for a 1ltr tin. Then you can paint wall. The whole project could be done for less than £50 time wise 1 day for washing wall then leave to dry for about 2 days sand & primer 1/2 a day

Jeepers_Creepers

Hi Jack.

As above.

You can't paint on to a bare wall?! Of course you can. I guess this person meant that it had to be in good, smooth condition.

Now you've got everything off the wall, what is the surface like? How many dunks, dinks, scuffs and blemishes? Could you post some photos of the worst parts so we can try and judge what needs doing?

Meanwhile, please don't PVA or anything the wall in anticipation of having it skimmed - leave ALL this to the plasterer is that's the way you need to go (and that quote is not unreasonable provided he's good and will give you a very good finish).

Also, as doneme says, skimming is one of these jobs that's not for the faint-hearted. For me, too, it's the hardest task by far, and I have to put in a huge effort to get a remotely acceptable finish - and that's usually afetr some sanding...

So, let's see what your walls are actually like!

jackspade

Thanks heres a pic, ill take better pics if needed

Those brown sections are the actual wall/rendering , its extremely smooth.  Is it worth washing the whole wall down to that state and then just PVA and painting on that?  The brown rendering has a few small dents , can they be filled with pollyfilla?

donemedosh

Well you have really cleaned that up good. I would sand it over just to get rid of any lumps or bumbs fill in any cracks the zinsser123 then paint saved yourself £500.

FreeBear

jackspade said:  Is it worth washing the whole wall down to that state and then just PVA and painting on that?

Yes, wash the wall down with a sugar soap solution, but do not slap any PVA on before painting... Not unless you want to peal the paint off in big strips at a later date.

If you are doing any sanding, wear a decent P3 dust mask and seal off the room - The dust gets everywhere and you really don't want to be breathing it in. Once finished with the sanding, get a spray bottle filled with water and spray a mist around in the room. The droplets of water will help the dust to settle and make the task of cleaning up a little easier.

jackspade

FreeBear,

no PVA before painting ? so I can just paint directly onto the smooth brown part of the wall? with some undercoat I assume first.

Also is it worth getting a sanding machine? if so which one? or I should just sand by hand with the trowel thing

Jeepers_Creepers

jackspade said:

Thanks heres a pic, ill take better pics if needed

Those brown sections are the actual wall/rendering , its extremely smooth.  Is it worth washing the whole wall down to that state and then just PVA and painting on that?  The brown rendering has a few small dents , can they be filled with pollyfilla?

The 'brown' bits are actually ready to take paint - that's what you'd end up with if you had the walls skimmed. If they are very smooth - 'polished' - then a light going-over with 120 or 180 grit on a flat block would be advised first. (And bare plaster should ideally be first painted with a slightly - ~15% water - thinned coat of paint).

For the rest - the areas with some paint still on them - it really depends on its condition, and whether there's a noticeable 'ridge' between it and the bare plaster - is there? If it's really the thinnest of remaining paint, with no flakiness, no raised edges etc, then it should be possible to roll a fresh coat of paint over it all.

Could you take a close-up photo at a low angle (facing towards the natural light source, window etc) to show what the painted areas are like, and the edges of it?

If you can get that wall free from raised edges, bumps and ridges, you are good to go. I mean go to the next stage :-)   So if a light sanding using 120 grit gets that wall generally flat with no raised bits, I'd be looking at applying a base coat of matt emulsion to even out the surface. Once this dries, you'll then know what else might need doing. Any dents - yes, you can fill. Then sand down the excess filler completely flat once dry. Roll a further coat of paint over it, allow to dry, and see how good it is. By doing this, you can almost always get to a perfectly good surface ready for the actual colour of your choice.

If there is any suggestion of the remaining paint being unstable - loose or dusty or flaky - then rolling on a coat of Zinsser primer/sealer first would probably make sense. There's a lot to choose from - not sure which is best, but I'd go water-based if possible.

Almost certainly you can sort this wall out yourself. At no stage whatsoever should you apply PVA to it...

daveyjp

Smooth off, I use an orbital sander with a fine grit paper, use a trade emulsion for the first coat.  You can water it down slightly if required, but its usually quite thin.

Norman_Castle

jackspade said:

Also is it worth getting a sanding machine? if so which one? or I should just sand by hand with the trowel thing

Whats a "trowel thing"? If hand sanding use a sanding block.