Lounge above Garage - air gaps at walls?

[GRC]

I've got a lounge above an integral garage, and the door of the garage faces into the prevailing wind.

The house was built in the mid 1990s, I assume to all current building standards of the time; the lounge has chipboard flooring panels on top of the joists, the garage has what appear to be standard plasterboard panels nailed below the joists. I assume there's insulation between.

The plasterboard panels down below have a 1-2mm gap to the brickwork of the garage wall. Up in the lounge, there's a gap between the skirting boards and the chipboard flooring. It's carpeted in the lounge, with the carpet secured and folded over grippers at the edge, but

In windy weather, I get draughts in the vicinity of the skirting.

Does the gap between plasterboard and wall in the garage HAVE to be kept? Does the space around the joists need to breathe?

Essentially, is there any reason why I shouldn't run a bead of silicone sealant all the way around the edge of the garage to stop the draught?

 

[holmslaw]

I think this needs further investigating.

You should have a 1 (or is 2?) hour fire barrier between the garage and the room above. If the fire barrier was correctly installed there would not be any drafts.

 

[GRC]

Where can I find the specification for what you reckon should have been installed?

I'm in Scotland, if that has any bearing on local variations in building regulations, etc.

 

[^woody^]

Not normal silicone, but an intumescent mastic should be run around the perimeter of the ceiling.

Their should be no gaps from the garage to other parts of the structure/property

 

[freddiemercurystwin]

The plasterboard is the fire barrier.

 

[GRC]

Should the plasterboard have been treated in any way, or is the standard stuff generally fire-resistant?

Intumescent mastic? Never seen that in B&Q, I must say - is there a brand or maker's name I should look out for...?

 

[freddiemercurystwin]

Standard is ok. Go to a builders merchant instead if B&Q have none.

 

[GRC]

Have a look - //www.diynot.com/network/GRC/albums/

Gaps around trunking for light switch and mains sockets, crude box section above door made from plasterboard, and general views of the gap between wall and plasterboard.

They also seem to have run out of plasterboard mid-garage - I have two different shades!

 

[GRC]

Come to think of it, should the intumescent mastic also be applied around the door frame of the door that accesses the hallway.....?

And should that door be a fire door, and if so, how do I tell if it is or not?

Thanks for all advice so far....

 

[freddiemercurystwin]

All plasterboard is fire resistant, fill the gaps with sealant or offcuts of plasterboard + sealant, fill any gaps around the dor frame, how thick is the door, if its 44mm its likely to be a fire door or it may have a sticker or other identification somewhere.

 

[GRC]

44mm thick, no identifying labels but either a white 'plug' or a plug that's been painted over in white (can't tell which yet) below one of the hinges....

No brush seals or rubber seals fitted to the frame or the door (I've been googling them, too...)

 

[freddiemercurystwin]

http://www.firesafe.org.uk/html/fsequip/firedoor.htm

 

[GRC]

Finally got around to the intumescent mastic, around the perimeter and along the joint lines between the plasterboard pieces, and the lounge is MUCH warmer now.

Thanks to all who provided info, much appreciated.

 

[JohnD]

Two other things that are worth doing:

You can get fire-resistant expanding foam (in an aerosol can - you squirt it through the tube into the gap like shaving foam, it expands, sticks, and goes rigid) is very good for sealing gaps and preventing draughts. It will also prevent smoke coming up in the event of a fire, as well as preventing the spread of flame. You can apply sealant, paint or plaster over it, and can knife or sand it smooth if you want. Dirt and dust, as well as draughts, come up the gap and can stain carpet and skirting.

As the room is above an unheated space, you can put mineral wool quilt (as used in lofts) between the joists of the floor. This will also slow draughts, as well as giving insulation, but it is better to seal all gaps with the foam first. The most convenient time to do this is when you are taking up the floor for plumbing or electrical work; or when that horrible chipboard cracks and creaks and you need to replace it with a proper material such as ply.

p.s. you can also inject this foam between the door liner (frame) and the wall. There is usually an uneven gap here hidden behind the architrave. It not only seals against draughts and smoke, but also (it goes in very sticky, expands to fill the gap, and dries rigid) it hold the frame firmly in place.