Which blocks for garage?

[Peter500]

I'm building a garage and a living room attached to my main property. The walls will be cavity walls with brick and block. My plans are all done for lightweight blocks ie. 3.6N and I was going to use the 0.15W/mK ones which should give a better U value. I'd like to leave the option of converting the garage to a room in future, so it would be nice to have a higher U value even though the extra little bit will make little difference as a garage.

I've realised that the lightweight blocks aren't 'paint grade' and chip easily. As the garage will be either fair face blocks or painted, it would be nice to have something that looks good. Equally, I want to hang some cupboards in there. Does anybody know what blocks would be best? Would the lightweight ones have bits chip off them over the years or would they look bad as soon as they're laid? The lightweight blocks also have the advantage of being easier to lay/handle.

So, what are people's experience with different blocks? Options for lightweight blocks include Celcon and YTONG.

 

[^woody^]

Any concrete block and good brickies.

It's a waste of time thinking about u-values for a garage. What about the door, the floor, the roof? The walls won't be doing much except holding the roof up.

 

[Peter500]

Any concrete block and good brickies.

It's a waste of time thinking about u-values for a garage. What about the door, the floor, the roof? The walls won't be doing much except holding the roof up.

As I mentioned in my first message, I want the option to convert to a room in the future, so the U value would then make a significant difference. The garage door and roof will be insulated, so it will be well insulated on the whole. It should make a big difference in the summer when the garage will be kept cool, which will also keep the room next to it cool. I've heard people say that it won't make a difference in the winter as it's not heated but I would have thought it would retain more of the heat from the house.

 

[Notch7]

As I mentioned in my first message, I want the option to convert to a room in the future, so the U value would then make a significant difference. The garage door and roof will be insulated, so it will be well insulated on the whole. It should make a big difference in the summer when the garage will be kept cool, which will also keep the room next to it cool. I've heard people say that it won't make a difference in the winter as it's not heated but I would have thought it would retain more of the heat from the house.

I would suggest doing cavity wall batts like rockwall. Then use 7.3 N concrete blocks and add insulated plasterboard or 50mm celetex when you convert.

If you really wanted to, you could put 50mm celetex in the cavity.

Or you could look at a different blocks like fibotherm or henelite which may be stronger than lightweight blocks like thermalise but better u value than hi 7s

 

[^woody^]

As I mentioned in my first message, I want the option to convert to a room in the future

Then you would line the internal face with a suitable insulation, and not worry about or now. An unheated garage does not magically retain heat from the house and be warm, it stays cold no matter what blocks or insulation is used.

 

[Peter500]

Then you would line the internal face with a suitable insulation, and not worry about or now. An unheated garage does not magically retain heat from the house and be warm, it stays cold no matter what blocks or insulation is used.

That's a good point. I had thought about using insulated plasterboard in the future, which would be more than enough to compensate for the less efficient blocks. It does feel like insulating from the inside isn't the best way to do things but I guess it's fine.

I'm sure that insulation must make some difference in the garage. For example, when I park my car in the garage it has never had ice on it and is always warmer than it would have been if it was outside.

So far Fenlite blocks seem pretty good. Paint grade, 7.3N/mm2 and 0.47W/mK . I would need to find a place that stocks them though.

 

[Old Salt]

Sorry, wrong thread!

 

[^woody^]

I'm sure that insulation must make some difference in the garage

It's marginal. The air finds its own equilibrium, but remember that insulation works on the basis of reducing heat loss through it over time, not keeping all heat in for ever. Likewise it keeps heat out on colder days (low solar gain) in winter.

If you've ever worked in a unheated building in winter, you'll experience it being actually colder than it is outside!