Best type of block to use

[alphazulu]

I'm just about to start building a wall using blocks and wanted some advice on the best type of blocks to use. The house originally had an internal garage and a second garage was added many years ago. The brick wall separating the two garages has been removed and a UB fitted. I want to replace the brick wall that was removed so I have two separate garages. The two garages will be used for storage (one for garden stuff and the other for household stuff) but in a few years I might convert one into a kitchen extension so I want to make sure what I build will be OK if I ever decide to go down this route. Which blocks would you suggest I use? The wall will be approx 4 x 3 m. The foundations of the previous wall are still in place and there are bricks at either end I can tie the new wall to.

My choices are:

100mm Solid Concrete Blocks - Solid concrete blocks, used for all hard building and landscaping. 100mm thick.

100mm Celcon Blocks - Celcon Insulation blocks. 450x225x100mm

100mm Fenlite Blocks - A standard medium density concrete block, 450x225x100mm.

 

[theprinceofdarkness]

I think I would consult the building regs about the fire safety rating of a wall between a garage and a kitchen. I am sure that they will call for 2 X 100mm concrete or brick. Also the shared roof structure. Otherwise I would go for 2 X 100mm celcon.

 

[alphazulu]

I found this from a council:

15.0 Wall where partly converting a section of a double garage
The wall that separates a garage/store from the new room/s will need to befire rated to 30minutes and thermally insulated to achieve a U Value of 0.28W/m2K
a) This can be achieve with a block cavity wall as detail 4.0 Infilling the
Garage door wall details a). This results in a loss of 300mm floor
area.
b) If a block wall is required then another option is to build a 100mm thickwall then add 60mm Celotex GA4000 or similar to achieve 0.28 W/m2K, these sheet should be tight jointed and taped, then fixed in place with a 25mmx47mm timber treated batten, this creates a service void for cables and pipes and finally add a 12.5mm plaster board and skim. The loss of floor area is about 200mm
c) An alternative is a timber or metal stud wall, with 75mm Celotex in a
100mm stud, a further 12mm Celotex TB4000 internally across the face
with plasterboard both sides, the garage side will need to be pink fire
line board, in order to strengthen this wall we advise adding 9mm
plywood to the wall before the fire board, the loss of floor now is about
150mm.
Note: These walls need to go full height and be fire stopped against the roof or floor above.

So I think a single skin of block will be fine in terms of fire safety. The two garages don't have a shared roof. The original has part of a bedroom above it and the second garage was built as an extension with a flat roof many years ago.