Attaching Plasterboard - am I being a div?

[rcd1976]

Sorry if this is covered elsewhere but couldn't find it in the wiki or any online idiot guide. Am trying to board some walls and ceilings. One the walls they'll mainly be going into studwork, and on the ceiling I'm using resilient bars for soundproofing. I'll get a pro in to skim at the end. In places I'll be using Fireshield, Soundshield and Moistureshield so please say if anything different applies for them.

Here's what I'm planning:

- Use two layers of plasterboard, making sure joints don't overlap
- Fix it with drywall screws. Can anyone recommend any? The little bit of boarding I had to do already I had a lot of trouble getting them flush. Is there a knack I'm missing? You don't need to drill a hole for them do you? I've heard 'double thread' ones might be better.
- Use jointing tape - what sort (paper?)? Do you tape both layers or just the outer one?

One other question: in a bathroom, should I go for Moistureshield of Vapourshield? I've put in Aquapanel for the shower, but was going to do the rest in board. Should I get a bit Aquapanel for behind the basin or is that overkill?

Thanks very much.

 

[PrenticeBoyofDerry]

- Use two layers of plasterboard, making sure joints don't overlap

why two layers? when you say don't overlap you mean don't meet, so do overlap?

- Fix it with drywall screws. Can anyone recommend any?

for metal
for timber

The little bit of boarding I had to do already I had a lot of trouble getting them flush. Is there a knack I'm missing? You don't need to drill a hole for them do you? I've heard 'double thread' ones might be better.

the screws should be slightly countersunk, set the torque on your drill accordingly.

- Use jointing tape - what sort (paper?)? Do you tape both layers or just the outer one?

don't use paper, use self adhesive nylon scrim joint tape. Only need to tape joint the exposed surface.

One other question: in a bathroom, should I go for Moistureshield of Vapourshield? I've put in Aquapanel for the shower, but was going to do the rest in board. Should I get a bit Aquapanel for behind the basin or is that overkill?

foil back for ceiling, moisture resistant for wall areas that could get wet. No need for aqua panel for basin.

This may help
http://www.zurich.co.uk/NR/rdonlyre...BF-4E5D5F270C8D/0/500045004BG900204WebOpt.pdf

 

[rcd1976]

Thanks very much, that's pretty much cleared it up.

By making sure joints don't overlap I meant that the joins on the first layer are in a different place to those in the second layer.

I thought you were supposed to use two layers of plasterboard. On the ceiling I'm doing it for soundproofing. It may also be because the stairs make it very difficult to get anything more than a 12.5mm sheet into the property (it's really awkward and if each sheet weighs more than about 15-18kg you'd be done in after a few sheets).

Ta.

 

[peaps]

Thanks very much, that's pretty much cleared it up.

By making sure joints don't overlap I meant that the joins on the first layer are in a different place to those in the second layer.

I thought you were supposed to use two layers of plasterboard. On the ceiling I'm doing it for soundproofing. It may also be because the stairs make it very difficult to get anything more than a 12.5mm sheet into the property (it's really awkward and if each sheet weighs more than about 15-18kg you'd be done in after a few sheets).

Ta.

You can add insulation for sound proof instead of double boarding.

 

[PrenticeBoyofDerry]

There is no requirement for two layers of board on the ceilings.
It will improve the acoustic qualities and fire resistance of the ceiling though.
Have you considered adding insulation or using soundbloc
If you do add insulation to the void though be careful in regards to covering electric cables as this will effect the current carrying capacity's of the cables.
What is the noise issue?

 

[peaps]

If you do add insulation to the void though be careful in regards to covering electric cables as this will effect the current carrying capacity's of the cables.
What is the noise issue?

Not so much of an issue if the wiring is upto date, but worth thinking about with shower, cooker cables etc

 

[PrenticeBoyofDerry]

Not so much of an issue if the wiring is upto date, but worth thinking about with shower, cooker cables etc

Still an issue regardless of when the cables where installed, normally lighting circuits are okay, providing the cables are being protected by 5 or 6amp devices. As the standard 1.00mm T&E can carry a maximum current of 16A, so even if worse case scenario of 50% de-rating will leave the cable safe to carry 8Amps, so 5 or 6amp protective devices makes it safe.
But powers circuit cables current carrying capacity are designed a lot closer to the current demand of the circuit and the rating of the protective device. So any de-rating of cable could mean up grades of cable sizes. Does not matter whether it's old or new installation.
For example an
A3 type radial circuit will have a 20A protective device on a 2.5mm T&E cable.
2.5mm T&E can can carry a maximum of 27A.
If this cable is routed through a ceiling, touching plasterboard and covered by thermal insulation exceeding 100mm.
The current capacity of the cable is then reduced to 17A.
17A cable on a 20A device is not permitted nor safe.
A3 type circuits are quite commonly installed as new.