60's Bungalow Extension - Garage Floor

Currently in the process of designing / drawing plans for an L shaped extension to a Bungalow. Current building is basically a box, new build will be extension rewards and to the side to give me a new large lounge and bigger 'attached' domestic garage/workshop. The new garage floor level will be set to meet an existing pre-fab workshop floor, whereas the floor for the new lounge will obviously be the same as the existing domestic rooms. The difference is around 100mm (new garage floor lower), so this should also meet building regs. When I come to spec the construction for BC I'm happy with the new lounge floor with regard to insulation etc, but it’s the new garage floor I'm unsure about. I would like the finished floor to be at least a 150mm slab with reinforcement in order to take the load of machinery (milling machine, lathe, two post lift, etc) and a car.

Although I will probably heat it by some external means (i.e. not part of the central heating), I’m not sure if I need or will have to have any under floor insulation? If I do, could someone give me an idea of type/thickness that would be necessary to support the slab above? I also have in mind that if I go with no insulation, and later decide that in order to sell the house I should convert some of this garage space to accommodation, I can add insulation and floating floor in the 100mm space mentioned above... hope this makes sense!

Thanks in advance.

i think it would be wise, bearing in mind the weight of machinery involved, to not bother with inso' at this stage. as you have already stated, a retro' fit of insulation at some later stage can be accommodated within the 100mm differential. the mass of the machinery may increase under operating conditions.

a later addition of say 80mm celotex plus 20mm floating 'deck' will deal with u value requirements should you ever wish to convert garage to habitable.

If the workshop will be on the other side of the wall from living room, think about how you will soundproof between rooms.
You'll soon be Mr Unpopular if you are milling away during Eastenders.

Thanks for the replies guys, very helpful.

Deluks - yes the workshop is currently planned to be on the otherside of a single block wall. I had thought about sound insulation, is this a building regs requirement in this situation? I'm personally not that bothered, as I live on my own

Thanks.

Eng33 said:

I'm personally not that bothered, as I live on my own

Thanks.

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ah, no worries then

any neighbours closeby though?