UKC

Back to mine the depths of ukc knowledge, plastering this time.

I've recently plastered 3 walls in the kitchen using wickes one coat plaster (tinyurl.com/onecoat) and it's looking ok, flat at least, one wall is quite smooth but the other two have got trowel marks in, a few bubbles and some little holes in places. The plan was to sand it down a bit afterwards but while i was working yesterday I went back over a small section I'd done last week with quite a sloppy mix and it looks great and smooth, it was wetter than I'd used it before and it seemed to press in quite nicely. It was only a small section though so the size made it easier. Anyway, I'm now considering skimming the rest of it and I wondered if someone could answer some questions.

1) The stuff I'm using dries white, is there much difference between that and the multi-finish which looks brown and what I'm using. (I was looking at tinyurl.com/qxt6hpd and tinyurl.com/qxyznpn). If I'm skimming over the top is it better/easier to use one of those?

2)The bit of plastered wall I skimmed over was completely dry, if I was to skim the rest would I have to wait for them to be fully dry as well, or can I do it in the next day or so?

3) I know this is a hard question to answer but is it worth doing or should I just sand it? My thought was that it might be easier to get it smooth now I'm doing it on a flat surface, but I could be wrong. If skimming is harder than putting that plaster on then I'd be tempted to leave it. It was hard to say whether it was easier or harder because it was just a small bit I did.

4) How the f*ck do you get the corners right? I've got both in and out ones and two short ones are fine but the longer ones aren't as straight as I would like. In hindsight I should maybe have got some edging strips as there doesn't seem to be anything underneath apart from a thin bit of metal at the edge which I didn't knock back to enough. I guess it's too late for that now, although I guess I got chip the corners completely out and redo them, bleurgh!

5) Thickness, I've watched a few youtube videos and there doesn't seem to be any consistency (sorry) with how thick people mix their plaster. Some guys have it wet and sliding off the trowel where as others seem stiffer and they're pressing it in more. At first I was mixing it so that at the start of mixing it was crumbly but then went to philidelphia cheese style. i found that easiest to work with but it dried very quick and I wasn't fast enough to smooth it. I tried mixing it wetter and I found it harder to work with, sliding off the trowel and I felt I had to be gentle with it on the wall or it would squish down. When i've watched people doing it they seem to talk about using a lot of pressure, which makes me think stiffer is better but maybe I should have put it on wet and left it to dry a bit then used pressure to flatten it.

Sorry for the long rambling questions, I'm aware I'm being cheeky basically asking to be taught how to plaster but any pointers would be much appreciated.

Thanks

In reply to Sharp:

Can't help with most of it I'm afraid. Other than to suggest getting a proper plasterer to skim it. The finish will be better.

However, the corners, especially the 'out' ones, really should have edging strips. If you don't and they get knocked about (i.e. when using the room) when you've finished then they'll look shite.

If you're going to fill / sand then don't use polyfilla - it's a nightmare to work with and sets too hard. Use Gyproc Easi-fill, the difference is incredible and you'll never go back.

In reply to Sharp:

Knock it off - start again - use beads for the outside corners and use a corner trowel [twitcher] for the inside ones. - Forget the one coat - use board finish or multi finish - Don't do half a job - you'll kick yourself every time you look at it.

TBH it sounds like you'd be better getting someone in to do it - It will work out better in the long run

In reply to Sharp:

I am a reasonably keen (not very good) amateur plasterer, and have made quite a few noddy mistakes but also got some reasonable (I was impressed) finishes in plastering our bathroom, and a few other bits and bobs. My tips are as follows:

1. Personally I prefer to use finishing plaster rather than general purpose. Use general purpose to fill and finishing plaster to skim. If you only have a small area, try to get smaller bags or just roll with the punch knowing there will be a lot of wastage.
2. Preparation is key. Ensure the area you are working in is free of rubble and loose bits and bobs. Many a time I have been plastering from the floor up and ended up picking bits and bobs on my trowel which ended up on my beautiful wall.
3. Always remember to prepare the wall with PVC watered down. Failing to do so causes some interesting effects. If you do forget, spraying the wall with water can just about get you out of jail.
4. Personally, I mix my plaster to the consistency of slop.
5. They key to plastering is leaving it to go off to the right consistency. This is where I fall down. But corners and the like are easy if you do get it right, using a damp cloth and your trowel.
6. You can sand plaster down afterwards, but you really don't want to.

Good luck!

PS - YouTube is your friend. Plastering isn't that hard, but I guess if you only ever do a bit here and there, you never get enough practice to get good at it.

In reply to Sharp:


Sanding plaster is much much messier than you can possible imagine. It also takes a lot longer than you might think and can be hard to get the finish you want.


I've always used multi-finish, as does the plasterer I've hired in the past. I wouldn't say it's "easy" to work with, but not having used the stuff you're using I can't compare.


Generally if plastering e.g. a fresh wall, you'd put a bonding coat on and then skim over the top. If the bonding coat gets too dry then it can suck the moisture out of the skim and it goes off too quick. Not having used one-coat I don't know if you'll have a problem with it being too dry, but don't worry about it being wet, so long as it's gone off ok (e.g. hard).


As mentioned above, Gyproc easi-fill is pretty easy to work with, and much easier than sanding messy skim. My (very amateur) advice would be: if you're going to use a filler, use easi-fill and target specific rough patches/trowel marks, don't try and smooth the whole wall over. It sands /very/ easily down to a smooth finish, so don't worry if you don't apply it perfectly just ensure that you fill the void in the plaster beneath.


Agree with others; corner bead for outside. For inside corners, don't try and do both walls at once; do one wall, wait for it to go off completely then do the other.


I tend to go for the thinnest mix that will stick to the wall. It thickens up as it starts to go off, so this gives the longest working time. Normally with a skim coat (of multi-finish), you slap a very thin (1mm) coat on as quick as possible, leave it to go off slightly while mixing your next batch and then apply that. By letting it go off slightly, it wont "squish" so much.

Note: I'm most definitely not a plaster. I'm self-taught and although improving some of my earlier jobs were really quite bad. Now I'm only fairly bad. I'm sure an actual plasterer would probably disagree with my advice.

In reply to ByEek:

Cheers, I'll give the finishing plaster a go. I'm quite happy with the finish for my first attempt at a big space, with sanding it would only be me that notices the imperfections but I'll give the finishing plaster a go and see how that turns out. It's quite enjoyable to do, although I recognise a few of those mistakes. I wish I'd spent a bit more time preparing the wall, tiny little bits of old plaster at the sides became a PITA.

Hopefully now I've got a flat area to work on the skimming will go ok. I'd be interested to know if I can skim over the base plaster now or if I'll have to give it a week or so to dry out.

csw - I'll get some edging strips for the sides and I might invest in one of those corner trowels. If I've got the strips on then patience and a scraper might be ok though. FWIW I think getting a plasterer in would be better in the short term, not the long term. Long term if you never learn to do stuff you'll end up paying someone else to do it over and over again for the rest of your life. I'll give it a shot and see what happens, I think plastering is one of those things that's impossible to get as good as someone who does it day in day out but maybe flat and smooth is attainable, which will be good enough for me.

In reply to ByEek:

Couple of points - Don't plaster all the way to the floor - that's how you pick up grit etc - the skirting boards will be covering that part anyway, so stop a couple of inches short.

The secret isn't waiting for the plaster to go off to the right consistency, so much as it is mixing to the right consistency [quickly] and getting on the wall as fast as you can - as soon as the first bit of powder hits the water you're on a timer - you really can't afford to wait for anything.

Also - without looking at the wall, it's hard to tell what the job is going to entail - the finished product is only going to be as good as the weakest thing it's stuck to.

If in doubt mix your plaster slightly thick - you should be able to run your trowel through it and have it leave a trough behind it - If the stuff is like soup it will go everywhere and you'll never get a consistent coat - Too thick and it will go off before you're half done - but if you can get a friend to mix for you and keep lots of small batches [black builders bucket] coming constantly, that might work well.

Once the stuff is on the wall, it needs to be trowelled up - that's where the real work is - I assume that's what you're doing?

Anyway - I'm not saying I'm the worst plasterer in the UK, but I'm probably a contender, so treat my words accordingly, but if you want to PM me then feel free - If you lived closer to Preston I'd probably even lend you some tools

In reply to gav:

Cheers for the advice. I've only sanded small jobs down before but not really found it that messy to be honest, the dust seems quite heavy so it just collects on the floor for sweeping up and hoovering. Maybe a bigger stretch of wall would be worse.

Thanks for the tip about putting a thin coat on first and then smoothing over with fresh, I'll give that a try.

In reply to csw:

Cheers, all the old loose plaster was knocked back and it seemed quite stable after that. (That could have been on your advice on a previous post when I asked). It's quite awkward spaces which is probably as useful as it is annoying, i.e. it's quite awkward to get in the spaces and there's thin strips of wall that are the wrong size for my trowel...but I wont be looking at a full wall when it's done it'll mostly be hidden by cabinets, shleves and appliances which probably makes the whole thing a bit more forgiving.

In reply to csw:

Excellent points well made. Yep - I have discovered most of those tips through trial and mostly error. The concept of plastering is so simple. The reality is another thing all together!

Cheers for the advice.

In reply to Sharp:

with regard to the small spaces, a couple of tools that might help are a Margin trowel and a small tool, which any builders merchant will sell you - You'll probably pay about £30-00 for them, but if you plan on doing any more plastering, then it's worth buying them. A pointing trowel is pretty useful too.

As for when you can put another coat on, I don't think you need to wait - but make sure you coat the wall with PVA first - One thin coat, followed by a slightly tacky one - Do not let the PVA get into your plaster and don't skim onto it while it's wet - But I bet you know that already.

In reply to Sharp:


It probably depends how bad it is. My first few walls needed quite a bit of work with a power-sander. As my plastering has improved I don't need to smooth up as much anyway, but nowadays I just go round when it's dry and use a thin easi-fill mix to patch in the odd trowel mark. I sand this very lightly by hand and don't make too much mess.


The key to this is to get the first coat on very quickly. Don't worry about smoothing it, though obviously try and avoid bubbles etc.

In reply to csw:


I do now! I've thus far let the pva dry first but not out of any master plan, watching my plaster slide off the wall could well have been one of those learning experiences so thanks for the tips.

In reply to Sharp:

Get on you tube, I was a plasterer for 8 years. Don't listen the the advice given above.

PVA needs to be slightly wet or the plaster won't bond to the wall, and WILL come off without much effort.

The trick with plastering is not to mess about with it once it's on the wall to much.

It's going to take around 2 hours to trowel up

Usually about 5 trowels

Don't throw to much water onto the plaster

Brush in all the edges

Leave at least 15 mins between each trowel

Buy a decent perma shape Marshall town trowel (partly broken in)


I hate people who normally say this, but you really should get a plasterer in, there are to many variables for things to go wrong. It takes years to become competent at plastering.

In reply to Sharp:
Top tip get a plasterer to do the job , I'm a plasterer mind you
Don't think a good plasterer would go near your place as you
Already no it all
Cheers Mark

In reply to Sharp:

You can't see all the irregularities in a newly plastered wall unless you're a plasterer, and even then not everyone is absolutely top notch! The best way to see how good a finish is is to get a mist coat of paint on the wall once completely dry. If you've only got a couple of trowel marks then just sand them out. I used some tape/fill compound to finish off a wall in our house prior to decorating(Badly skimmed chimney breast, and as the compound was free, and we rent,there was no way I was paying for a plasterer). The compound goes straight on to the painted wall and then sanded flat.

As the previous couple of posters have said(in a roundabout way), if you're looking for a professional finish, get a professional to do the job.