Help, What costs more Concrete or wood foundations?

Question

I am adding an extension on the end of my bungalow and so have to make the decision on wether to have Concrete or have a Wooden frame supporting chipboard flooring. The house sits about 18 Inches above ground level. The area of the new foundation will be 6125mm X 3500mm. But what is Cheaper?

Answer 1

You have probably found out by now that what you are trying to describe aren't called foundations. I think you should use block & beam construction for the floor,it's concrete "T" beams laid 18" apart & filled with 18"x9"x4" concrete blocks

Answer 2

I would be surprised if the local planning authority will allow wooden foundations at all?

concrete while more expensive is durable and weather resistant and will make it a lot easier to sell the  place later.

I assume  that you are aware you need planning permission for most extensions and at very least a building regulation compliance ? please check with your local council who will advise you and it is normally free I understand for outline  advise ( they wont tell you how to build it just give you basic outlines such as  NO wood or Must have concrete at least 182 deep for a width of .. etc)

Answer 3

Seriously if you are asking questions like this you need professional advice.

Answer 4

Cost is not the major consideration. You must use concrete piers to support the deck. Make sure the concrete foundation for the concrete pier is adequate size. I'd recommend 18" diameter by 18" deep concrete. Use pressure treated wood for the frame of the deck. This will prevent rot and termite damage. You can use any wood for the deck but protect it with double coat of polyurethane.

Answer 5

i don't where you live Mathew ..but wherever it is the answer is concrete every time ..unless you live in a very dry climate ..and then it would need to be tanilsed timber ...and if you use chipboard make sure its the green one ..its waterproof

Answer 6

Depends on where you are at? Since you are useing metric I assume not USA.Assumeing you have a plan then price the lumber (for a pier&beam) then price a turn key on a slab.a Wooden frame is more versitle(if you want to put in plumbing later) but subject to rot/termites/woodworm.But , a wood frame won't feel as solid under foot even with x braceing,and is noiser.I prefer pier and beam because my wife makes me move the kitchen every 15yrs or so.