garage / shed

irelandhouse

hi just wondering if anyone has any experience or advice to lend on this.

want to build a block shed/garage in the garden about 4.8x3.6m.

wanted to put in a cut or truss roof to use the roof space.

was going to do a cavity wall structure on a concrete slab.

my questions would be :
on the slab, would 25n20 be ok for this structure, about 150mm.
= I was going to do a straight slab all round.
wasnt going to bother putting in footings ? is that silly ?

starbelgrade

A slab without footing is perfectly fine for a garage - just thicken up the edges of the slab to support the weight of the walls to about 200/225mm.. a base of 125mm is enough, with a sub-base of at least 150mm.

starbelgrade

Also - allow for a control / expansion joint halfway along the length of the 4.8m run. Just wondering - why bother with a cavity wall? Hollowblock would be a lot quicker & easier to construct.

irelandhouse

starbelgrade wrote: »

A slab without footing is perfectly fine for a garage - just thicken up the edges of the slab to support the weight of the walls to about 200/225mm.. a base of 125mm is enough, with a sub-base of at least 150mm.

Cheers for that

so just to make my dummy's guide!

150 subbase of what would you think ?
150mm of 25n20 with wire mesh through with 225 deep at edge - how wide should this be ?, 100block+100cavity+100block=300 ?

irelandhouse

starbelgrade wrote: »

Also - allow for a control / expansion joint halfway along the length of the 4.8m run. Just wondering - why bother with a cavity wall? Hollowblock would be a lot quicker & easier to construct.

to be honest I want the option of possibly converting it at some stage,

was going to
100 block,
100 cavity,
membrane
osb,
stud,
plasterboard.

however if im going this far, I would be silly not to insulate the floor.

starbelgrade

irelandhouse wrote: »

Cheers for that

so just to make my dummy's guide!

150 subbase of what would you think ?
150mm of 25n20 with wire mesh through with 225 deep at edge - how wide should this be ?, 100block+100cavity+100block=300 ?

Hoggin, a natural mix of gravel & sand is an ideal material for a sub-base, but you can use crushed stone or brick. Just pour the harcore into the framework, rake it fairly level & tamper it down with a plate compactor (which you can hire) or a heavy balk of timber.

Break an y stubborn lumps with a heavy hammer & fill in any low spots with more hardcore or sharp sand.

The width of the edge should be the same width of the walls it's supporting, so yes, 300mm in your case.

starbelgrade

irelandhouse wrote: »

however if im going this far, I would be silly not to insulate the floor.

True!

irelandhouse

starbelgrade wrote: »

True!

thanks again for the replys on that, would you have an recommendations on this for the insulated slab.

for that would you be best to go with the footings around edge?
hoggins, sand, insuation,slab ?

starbelgrade

PM me with your e-mail address & I can send you on a section detail - it would take me a long time to try & explain it!