Repairing Walls Ready for Skimming

[jonwestuk]

Hi

I am in the process of renovating my house and this has included removing some walls and replacing some parts of the plasterboard walls and ceiling where there was significant damage. I am planning on getting a plasterer in to undertake a final skim coat and want to prepare the walls as much as possible to ready for him to skim so that I can get more walls done with my available funds.

The question I have is, where I have sections of new plasterboard there is a 5mm difference in the depth of the wall/ceiling to the old walls. Could you please advise me what preparation you would recommend in this case?

- I can scrim tape the gaps and screws and PVA the walls.
- I could also plaster the walls up to the same level as the rest of the wall and use my feather edge to make sure it is level. I have done this already where I had bare brick that I have had to prepare.

What are your views? I can imagine the easiest walls to plaster are ones that are already the same depth?

Finally, if you do recommend levelling the walls, what is best to use? I have both browning plaster and multi-finish open for a few other jobs I am doing. It looks like the backing layer of plaster on the original walls is a grey version of bonding plaster as it is more crumbly than finishing plaster.

Thanks for your help,

Jon

 

[roy c]

leave the prepping to your plasterer

 

[jonwestuk]

leave the prepping to your plasterer

That isn't really a helpful comment on a DIY forum

 

[roy c]

You asked a question, I gave you an answer that I felt was appropriate. You will find that a lot of plasterers wont touch work that has been prepared by someone else. You had better ask your plasterer if he is happy to follow on from your "prep"..

 

[jonwestuk]

My plasterer is more than happy for me to do the prep. He talked through a couple of things to do such as using bonding and PVA to fill the really large gaps in the walls, but there are now questions that I didn't have previously. One way that I keep all my tradesman happy and willing to work with me, is to keep their lives simple by not bothering them with lots of questions. Instead I look and research online, then use forums where I cant find the answers. The positive of that is that the response then remains on the web for other to also use.

So the question remains, should I fill the gaps on the top of new plasterboard and what is the best type of plaster to use for this? Any thoughts anyone?

 

[roy c]

I would get your plasterer to teach you how to skim, as skimming is a lot easier than prepping.!!

 

[jonwestuk]

Thanks for the advice, but I am still going to do the prep work myself as having started it now I am realising that it is within my capability. I had a plumber round today and he has some plastering skills himself and said that my work was more than sufficient to skim over.

 

[stevethespreader]

leave the prepping to your plasterer

That isn't really a helpful comment on a DIY forum

roy gave you the best answer any botch up or failures made by your plasterer can now be blamed on the prep work

 

[jonwestuk]

Aren't we a cynical bunch!

I will now try to answer my own question based on the research I have done as everyone here seems frightened at the prospect of anyone preparing a wall for plastering. From my perspective there is lots here that the average DIYer can do so I am not sure why some of this could not have been called out.

This is my plan thus far:
- Plug sockets and light switches will be removed and terminated and Blank-It card installed in the backplates.
- Light fittings will be removed where possible and unscrewed from the ceiling, then they will be covered in plastic bags to protect them..
- Raw plugs that are not in use will be removed from the walls as will other pieces of wood or silicon.
- Raises in the plaster will be cut off or smoothed out.
- The walls will be wiped down for dust and any cavities hoovered out.
- Sections of new plaster will be coated in 50:50 PVA and levelled with bonding plaster. The level will be maintained using a 2m+ feather edge.
- The surrounds of back plates, and any chases will be PVA'd with a 50:50 mix and plaster cement will be used to fill the hole (easier to work with than bonding).
- Once dry, I will PVA the walls with one coat of 25:75 Water and PVA and a second coat of 50:50. Area with gloss paint will have sand added to the PVA for better adhesion.
- metal beading 3mm deep will be nailed to the outward facing corners. Galvanised nails will be used as fixings.
- The room will be swept and roughly cleaned.

That about summarises the plan so far. None of it seems overly taxing as I have done all of this before on different tasks.

The walls seem to be pretty much flat and square so I don't think I need to do much in that respect. That is the only bit that I have not yet researched how to resolve, so for completeness sake it would be useful to hear how the pros flatten uneven walls.

 

[stevethespreader]

I will now try to answer my own question based on the research I have done

well done the only man on here to post questions and answer them himself top marks

so for completeness sake it would be useful to hear how the pros flatten uneven walls.

do some more research and come back and answer your own question again

 

[jonwestuk]

do some more research and come back and answer your own question again

Friendly

 

[NickB_99]

do some more research and come back and answer your own question again

Friendly

Jon, as a DIYer myself too, I am always keen to have a go at stuff where I can.
The guys on this plastering forum are a very knowledgable and helpful bunch.
Over the last few years, they have helped me from a complete novice to a reasonable plasterer, capable of a range of plastering skills. Really for my own home or family/friends tho - I don't think I'm up to the speed required for pro work.
Simply - you have got off on the wrong foot.

The list of stuff you researched is a good start. If you had led with this and asked for feedback, you'd have got further.

For me, I would offer a couple of points on your plan:
I would say the pva ratio of 50:50 is more concentrated than needed.
Putting sand in pva may help a physical key, but as pva is water soluble, there is a danger putting wet skim on that it may release some the sand back and mess up the finish. I prefer a decent bonding agent (WBA etc). This can be skimmed dry.

It is a DIY forum, but a lot are freely giving advice from their trade.

 

[jonwestuk]

do some more research and come back and answer your own question again

Friendly

Jon, as a DIYer myself too, I am always keen to have a go at stuff where I can.
The guys on this plastering forum are a very knowledgable and helpful bunch.
Over the last few years, they have helped me from a complete novice to a reasonable plasterer, capable of a range of plastering skills. Really for my own home or family/friends tho - I don't think I'm up to the speed required for pro work.
Simply - you have got off on the wrong foot.

The list of stuff you researched is a good start. If you had led with this and asked for feedback, you'd have got further.

For me, I would offer a couple of points on your plan:
I would say the pva ratio of 50:50 is more concentrated than needed.
Putting sand in pva may help a physical key, but as pva is water soluble, there is a danger putting wet skim on that it may release some the sand back and mess up the finish. I prefer a decent bonding agent (WBA etc). This can be skimmed dry.

It is a DIY forum, but a lot are freely giving advice from their trade.

Amazing advice, thanks so much. I will definitely alter my plan based on it. Still don't think I will be up to the final skim. My plasterer really gets excellent results so would much prefer him to do that.

 

[roy c]

As you say your plasterer is happy for you to "prep" for him, so why don't you ask him to give you a few tips on skimming, It is not rocket science and do what newbie did and practice and ask and more practice, you don't have to get to "Pro" standard to do your own house or friends and relatives projects. If you are shown by a pro you will have the basics to work on and you will start to get good results when you learn the skimming technique. But people like you (with a bit of knowledge )can progress and get further on by watching and asking, hands on, You are better to be shown than told how to do it on a forum. But if you look thru the plastering forum you will find most answers to all your questions,, And a few of us have albums up so you can see how some projects are carried out.