Double Slabbing

Carb

I intend double slabbing the walls of my TF house and then taping and jointing. I was wondering is it possible to screw the first slab on and then glue the second sheet, as this would mean less screws and cuts when it comes to the taping and jointing. Or would I be better screwing both sheets on?

Corkey123

Why would want to glue the second slab on?. The plaster board screws are not that expensive. You need not use the nomal amounts of screws on the first course of slabs and use the normal amont on the second which will bind the first course and course together( once the screws are long enought of course - suggest 50mm screws. You'd be mad to use glue/adhesive as you could be left with small pockets created by the adhesive between the slabs.

CJhaughey

I double slabbed and screwed both slabs.
don't even think about gluing!
You will need 50mm screws to do this, I have a lot of collated drywall screws left over after my build, PM if you are interested.

Carb

MartinCorcoran wrote:

Why would want to glue the second slab on?. The plaster board screws are not that expensive. You need not use the nomal amounts of screws on the first course of slabs and use the normal amont on the second which will bind the first course and course together( once the screws are long enought of course - suggest 50mm screws. You'd be mad to use glue/adhesive as you could be left with small pockets created by the adhesive between the slabs.

Nothing to do with the cost of the screws, and I'd suspect the glue would probably be as expensive. As my post said, if the second slab was glued on, there would probably be less cuts, for taping and jointing, and there would be no screws down the centre of slabs that need filling. I only asked to see if anyone had thought about this, as I've heard of people regularly sticking plasterboard to plastered walls. Obviously, if people advise that gluing is a bad alternative, it'll be screws all the way. Thanks for the replies.

Viking House

We line our Closed panel Timber Frame houses with Fermacell or Sasmox boards which is stronger than 2 sheets of plasterboard and doesn't need plastering.

CJhaughey

What price is the sasmox board?
Last time I looked it was more than 3 times the price of slab.
seems like an expensive way to cover walls, and double slab still gives better sound attenuation.

dixiefly

Viking House wrote:

We line our Closed panel Timber Frame houses with Fermacell or Sasmox boards which is stronger than 2 sheets of plasterboard and doesn't need plastering.

Excuse my ignorance but what has strength got to do with it? The OP is probably not double slabbing for strength reasons. It is more likely because of thermal or sound insulation.

beolight

if sound insulation is your main criteria here Carb

you should really be trying to decouple the rooms

lots of stuff here explains it much better than i couldhttp://www.audioalloy.com/understandingHowDecouplingWorks.php

also gypsum do a sound proofing board now cant remember the name of it but do a search or give them a call

agree that SASMOX boards are dear but might be cost effective when you figure no plastering needed and no mess

Carb

My reasons for double slabbing are two fold. One is for the more solid feel of two slabs, ie when you tap the wall, it won't just seem as paper thin. The main reason is sound insulation. I had asked on this forum before whether anyone had use gypsum's soundbloc slab, but everyones experience to date was with double slabbing, so I was thinking along the same lines. If anyone thinks I can get the same effect with different products, but less work (within a reasonable budget obviously), I'm open to suggestions, as slabbing once is bad enough, but having to do it twice is not something I'm looking forward to.

Corkey123

Carb

Double slabbing is definitely the way to go for both solidity and noise reduction. Just one reminder you will have to get wider door framing. Traditionaly 4 1/2 inch (10 CM) will not be wide enough. Suggest 5"

Viking House

Carb wrote:

My reasons for double slabbing are two fold. One is for the more solid feel of two slabs, ie when you tap the wall, it won't just seem as paper thin. The main reason is sound insulation. I had asked on this forum before whether anyone had use gypsum's soundbloc slab, but everyones experience to date was with double slabbing, so I was thinking along the same lines. If anyone thinks I can get the same effect with different products, but less work (within a reasonable budget obviously), I'm open to suggestions, as slabbing once is bad enough, but having to do it twice is not something I'm looking forward to.

We have recently changed our system to deal with the hollow knocking sound in timber frame houses, the frames now arrive on site with the OSB visible on the inside which we tape and joint to make the house airtight. Then we fit all the electrics and plumbing on site, we then line the inside of the OSB with 30mm Softboard between the conduits and put the plasterboard or Fermacell against the softboard on the inside.
When we knock on the wall it feels really solid because you have OSB, Softboard and Fermacell screwed together like a sandwich and you can fix screws through the softboard onto the OSB.

Any comments welcome!