Converting Integral Garage

[AntonyHarrison]

Some advice please as wanting to convert my integral double garage into a games room.
Walls are double thick with breeze block inside and brick to the outside to match the rest of the house. there are no signs of damp at all in the garage and in the 12 month i have been in there nothing in the garage has become damp, including papers and materials.

Will I get away with putting insulated plasterboard directly to the breeze block rather than building a wooden frame to attach to?

 

[^woody^]

Define "get away with"

 

[AntonyHarrison]

Apologies and edited; Would it be satisfactory for me to put insulated plasterboard directly to the breeze block rather than building a wooden frame to attach to?

 

[^woody^]

It is an accepted method, but the issue will be that it may not be enough insulation to meet your expectations or keep the room warm, and it definitely wont meet building regulations.

 

[Dodgyrog]

Can I just check - when you say "Double thick" does this mean a cavity wall - or just a double layer wall? - seeing as you are saying it's breeze block and brick I'm thinking you mean cavity but I may be wrong.

Just interested as I am approaching a very similar situation, but the section of external wall of my integral garage is cavity wall, with cavity insulation, and then rough plastered internally so I was aiming to just have that bit skimmed on the basis the existing wall / insulation is suitable (as per the rest of the house).

Thanks

 

[^woody^]

Normally, a garage conversion will need to meet current insulation values, not just be the same as the house.

 

[Dodgyrog]

Normally, a garage conversion will need to meet current insulation values, not just be the same as the house.

Got ya, cheers. I'll happily / easily tweak things, no prob at all. If current wall make up is external brick - cavity (with aftermarket blown insulation) - clinker block - 1/2" thick plaster.... what thickness insulation would you recommend? And although the wall doesn't feel too cold would you still recommend foil backed PB? There's also currently an old aluminium frame window in that section of wall too which will be replaced with a new double glazed unit. Should I take the extra insulation round the reveal as well - or could I keep the existing window width, maybe just run PB up against existing reveal?

Thanks for the advice - though does seem a bit odd that less than 1/20 of the bungalow's external wall perimeter will end up more insulated in an already warm house - but I spose I get it why BC take that approach.

Sorry to the OP for hijacking his thread but hopefully this adds some extra info for him.

 

[^woody^]

The rules with conversions is that you make best efforts to insulate to current standards. Sometimes it can be argued for a lesser standard, and if the existing house appears to be warm enough, then perhaps that's an argument to make. But generally if you are doing some building works, then the inspector will expect some additional insulation, and if you are going to spend time and money insulating and will be losing 50-75mm of space anyway, then IMO you may was well fit as as much of an efficient insulation as you can, and not just fit the minimum that building regulations require. Silver foil backed PIR is the most efficient, so at least 50mm of that.

Revels should be insulated and damp-proofed as good practice. It does not need to be as thick as the walls though and can be as little as 5-10mm. It all depends on the detailing.

Foil PB is not needed regardless

 

[Dodgyrog]

The rules with conversions is that you make best efforts to insulate to current standards. Sometimes it can be argued for a lesser standard, and if the existing house appears to be warm enough, then perhaps that's an argument to make. But generally if you are doing some building works, then the inspector will expect some additional insulation, and if you are going to spend time and money insulating and will be losing 50-75mm of space anyway, then IMO you may was well fit as as much of an efficient insulation as you can, and not just fit the minimum that building regulations require. Silver foil backed PIR is the most efficient, so at least 50mm of that.

Revels should be insulated and damp-proofed as good practice. It does not need to be as thick as the walls though and can be as little as 5-10mm. It all depends on the detailing.

Foil PB is not needed regardless

Nice one, much appreciated.

 

[AntonyHarrison]

Can I just check - when you say "Double thick" does this mean a cavity wall - or just a double layer wall? - seeing as you are saying it's breeze block and brick I'm thinking you mean cavity but I may be wrong.

Just interested as I am approaching a very similar situation, but the section of external wall of my integral garage is cavity wall, with cavity insulation, and then rough plastered internally so I was aiming to just have that bit skimmed on the basis the existing wall / insulation is suitable (as per the rest of the house).

Thanks

Its cavity wall, have checked and deffo cavity, along with damp proof course in there too