Dry Lining Garage Wall

I am looking to dry line a single skin garage wall to provide both heat and noise insulation for use as a workshop. I believe that I am fine affixing studs to the wall, inserting insulation and lining with plasterboard but I'm not sure of ventilation/vapour barrier requirements (I also aim to board and insulate the roof space). I have a number of books but am unable to find any clues with respect to the vapour barrier/ventilation detailing issue. Any suggestions please? Regards Peter

Reply to
Peter J Elliott
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I have a number of books but am unable to find any clues with respect to the vapour barrier/ventilation detailing issue.

Any suggestions please?

Regards

Peter

Reply to
Colin Jackson

My understanding is that you should place the insulation on the cold side of the vapour barrier.

If the insulation is on the warm side, then warm air can infiltrate into it, and water will then condense inside the insulation, since there is a temperature gradient inside the insulation.

When I did this to my garage, this was the setup:

Inside the Room -> OSB sheeting -> Vapour barrier -> Insulation ->

Outer wall.

Reply to
Mr Uncalled-For

Is the insulation necessary?

If you put wooden battens on the wall, then use foil backed plasterboard, the air will form quite a good insulation on it own. The air gap needs a small amount of free ventilation or the timber battens will rot!

Fibreglass only insulates because of the volume of air trapped in the pile. If you stop the air movement by sandwiching insulation in the gap, you will increase the rate at wich the battens rot. If you happen to hit the dew point of the entrapped air halfway through the insulation, the rate of rotting could be quite phenomenal!

The other way is to batten the room and line it with T&G board, this should give enough inulation between the tongues and grooves, it doesnt need much!

If you line it with wood you have a starting point for all the things you will want to screw on the walls of a workshop!

John

Reply to
John T

It was really cold when I decided to board out the garage, so I decided to insulate!

The point of the vapour barrier is to isolate the insulation from warm (moisture carrying) air. This is for countries where the outside temp is normally less than that inside.

Reply to
Mr Uncalled-For

That is the choice to be made, i used to have a desperately cold workhop as well! The thin layer of air (Like in double glazing) is quite effective without the cost, complexity, and other problems that might come with insulation. If you doubt me, look up some "U" values.

Agreed, this happens often with occupants breathing out moist air, like on a steamed up bus! BUT i was warned about this by a local (Wirral) building control officer when dicussing an unusual attick insulation problem.

The vapour barrier is put in to protect the insulation.

In a general or woodworking shop i would line the inside with timber (or plywood), leaving a mall air gap occasionally, like top and bottom, i would make it substantial wher i was likely to want to hang things.

Although it i normal to place a vapour barrier on the inside, for a low occupancy workshop, i wouldnt bother with inulation as such, so the barrier is superflous. A layer of fibreglass in a wood sandwich will not have a greater thermal efficiency than just the sandwich! In a low occupancy shop, with insulation as well, you might need vapour barriers inside and out!

John

Reply to
John T

Hi John. I haven't finished the job on my garage yet, so given what you're saying I probably wont bother insulating the bits that are left. The biggest source of cold is draughts from outside, so one aim I have is for the boarding out to get rid of the draughts. So I probably wont leave air gaps and will still use vapour barrier.

Reply to
Mr Uncalled-For

Thats your choice, and your property! personally i would leave a small amount of ventilation at the top and bottom of each gap (asuming vertical battens), it doesnt need to be much, a couple of quarter inch holes in top and bottom is probably enough,unless its really draughty through the wall from the outside you wont get much draught os the inside! If the wall is letting through evere draughts somewhere you have a different problem!!

If you ant to look at some really classy ventilators of this type, go up to Dundee and have a look around Captain Scotts "Discovery", although there are all sorts of examples of good ones in victorian buildings and so forth all over the place. We can learn a lot from some of the old boys!

John

Reply to
John T

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