Plasterboard and skimming question

Sep 30, 2008 20 Replies

When using straight forward square-edged boards (not tapered) and am having a skim over the top, do I need to use jointing tape?


If I don't and skim over the boards and joints with Multifinish, me thinks the hairline cracks will begin to show on all joints.


Am I correct? Have been around plastering on many jobs and never paid attention to that detail!!


You use scrim tape (course nylon netting). (Jointing tape is a more general term that includes other types.)

Depends how well you have fixed the board edges. Scrim tape won't completely prevent hairline cracks, but should keep them small enough to vanish when painted.

I can't do ceilings cos of me back :-( but I'd run a bead of silicon sealent along the edges and butt up with each plaster board then put a jointing tape over. This will definatly stop cracks appearing unless the the floor above is reapeatedly jumped on. :-)

NO> it wont take paint. Use decorators caulk.

But that is no real solution either.

its te tape that does what you want. Spreads the load.

Erm! he's skimming over the boards, the tape will hide the sealent.

but wont stick to it.

Silicone sealant should only be used where its the final flexible unpainted waterproof surface.

Fore everything els there is..well not barclaycard, but another approach...

What part of it don't you understand?

Put a beading of sealent along the edge of each PB butt up each PB and screw to ceiling,wipe of an excess sealent then put the tape over the PB edges.

It's not rocket science.

It's the wrong type of filler for multiple reasons. If the boards are screwed to the same timber along the edge, nothing is required. If the edge is floating, you need a solid filler, not flexible. I prefer to leave enough gap so you can force plaster bonding coat through, which will rigidly bond the board edges. If you just have a small crack between floating edges, just force the finish coat plaster in the gap as you skim the ceiling. In all cases, use scrim tape along the joins too.

It does not matter - as soon as you wipe the silicone you will be left with a thin layer around the joint. then a few months later, after skimming the plaster is likely to crack and fall off in these areas. Silicone is the wrong sealant for the job.

Can you understand this perspective?

cheers

David

No use trying to tell me because I've done it in the past hence why I mention it ie it works.

even you cannot understand that we cover the joins with tape so that plaster makes no contact with any of the sealant.

Sheeeesh!

You may be happy with this, but I think you'll find most people prefer the correct tool for the job when it is available.. silicone here is just a bodge.

Have you done any serious plastering over 2 years and I dont mean little patches here and there? and whats the correct tool for the job?

If you do bodges like that you can't have done /any/ serious plastering. silicone under tape is a serious bodge, it hasn't the strength to prevent the finish from cracking.

I've never seen a plasterer using silicone - can't see any reason why you would want to but I'm sure it will have no effect either way if taped over, so carry on if you want to!. Not sure what you mean by tool but a plasterer would use self-adhesive jointing mesh tape over the joins and then skim.

Neither has just leaving it without the sealant has it the strength. As much as Id like to show you my serious plastering, believe me when I say this I have been congratulated by a time served plasterer on my plastering ie walls that span 10'x12' my best comes when doing archways as I like doing them.

No-one was commenting on your plaster finish (which we have no reason to suppose isn't excellent) or doing archways (ditto), just your habit of using silicone! It's not a crime nor is it bad, but, with moderen jointing tapes (or, in the old days, properly applied jute scrim tape) it's just unnecessary in many people's opinion.

Its not a bodge. Its totally useless thats all.

What has that got to do with anything.... or is it just time to change the topic??

It was a phrase- the emphasis should be that silicone is simply the wrong thing (tool) to use I thought you could work it out... Sorry that I was not literal enough for you to follow.

cheers

David

You seem to be doing a lot of spouting in here but I've yet to see any of your post relating to actually doing DIY work?

Well George

I've been around over the years, accounts change, the name on that accounts that I've used may also change, as do the PC's, if you've missed this then so be it.

But most importantly I have absolutely no need or desire to justify myself or my posts to you, and what you judge as some valid contribution.

cheers

David

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