Which plasterboard for ceilings.

Eastender

My builder thinks that 9.5mm plasterboards should be better than 11.5mm versions, which I think should be fitted but he thinks 9.5mm are usually fitted in ceilings. Is he right, though both are priced roughly the same.

For upstairs, I don't mind if it's 9.5mm but for downstairs ceiling I think the increase depth of 11.5 mm should offer more sound insulation. Am I right?

The builder is replacing lath & plaster with plasterboards and then skimm over it.

phill99

9.5 are used for ceilings. You don't really want to use them on walls as it willbe easy to put your hand through them!

Eastender

phill99 wrote: »

9.5 are used for ceilings. You don't really want to use them on walls as it willbe easy to put your hand through them!

Thanks phill for your comment,

It's interesting that you favour 9.5mm for ceilings but spoken to few more people and they have told me that the lower depth is no longer often used nowdays, and that 12.5 is now a norm for ceilings.

phill99

You're right. I was just onfirming that 9.5 wasn't appropriate for walls.

inthesticks

I'm not such what the builders motives were(could be many,availability,lighter,the assumption that they are cheaper) but 12.5mm is def more substancial for a ceiling.The choice of thickness of PB is also dependant on the spacing of the studwork/joists

southcoastrgi

like i said in a different thread if you are questioning the builders at this early stage you have employed the wrong "builder" i would always perfer one that knows what he is doing & speaks english.

bob_the_builder2012

As the works is replacement the rules state it must be equal to or better than before in regard to sound proofing and fire resistance. If it is an underside of a floor 12.5mm board is needed to achieve 30mins fire resistance, and this thicker, thus denser board also is a better sound insulator. If it is really a ceiling with a roof directly over the fire resistance and sound insulation rules do not apply. I would personally always use 12.5mm as it makes a better finished job.
As a tip I have recently found a website that has some specification drawings on it buildingnotice.co.uk
Wish you the best with all the dust
Bob

cyclonebri1

I seem to recall that you wanted extra sound insulation in a previous thread? in that case you know the answer, go for the 12.5mm, but to be honest the better option from that point would have been to have overboarded rather than strip and replace.

I'm just wondering how you got info from the builder considering he can't speak English?

Can I ask for anyone following your threads;

How much mess was made removing the lath&plaster?

Eastender

Thanks guys for your comments.

Ok, would tell him to install the thicker plasterboard on the lower ground floor and put rockwool between the joist, the thinner ones at the upper floor. Will phone the Building Control team on Monday again but last time they did not seemed to mention that it is part of the regulation, as it's not a loft conversion on an extension.

The mess seems to have cleared as he hired 2 skips had 2 extra people helping him.

yes, the bloody builder did some work for us few years ago in our flat, nothing major and he was recomonded by a friend, popped in yesterday saw he was tyring to sell our scrap metals, another thread on that, probably:o.

Yes, I should have gone with on overboarding but the wife was persuaded and he did not give us a (cheaper) alternative.:mad:

southcoastrgi

at least you are gonna win the MSE award for the most threads on one project.

Leif

Eastender wrote: »

Tanother thread on that, probably

Go on, treat yourself.