I'm costing out my new build which I hope to start later this year, once our current house has sold. In the meantime I'm pricing up the various elements of the build.

Our Structural Engineer has specified a reinforced concrete basement and suggested we use either traditional timber shuttering or ICF. I've priced up the ICF route but am struggling to find comparative costs for traditional timber shuttering, has anyone got any suggestions on which approach would be cheaper and by how much?

It is Phil Sacres' basementexpert.co.uk site. Unfortunately a massive amount of very useful information has gone in a recent update to the site which is a real shame as it was all good stuff. He has an account on here (GBF), and if you get in touch with him directly he can give you further information on his own timber shuttering system using scaffold boards which I don't doubt would be more competitive than ICF. ICF can be done well or done badly like anything else.

The architect has specified both a radon barrier and a waterproofing membrane for the basement, I know the radon barrier is needed and was wondering if I specified waterproof concrete, could I do away with the additional tanking membrane? We are in a limestone area so no groundwater issues.

Having read a number of basement web sited there is mention waterproof concrete, but then go on to suggest the use of waterproof concrete has to be closely supervised. I would have thought I simply specify the addition of a waterproofing addmix when ordering the concrete, or am I missing something?

''The concrete must be compacted so there is no gaps in it.

It is hard to stop water being added to the concrete to make it easier to lay, buy any added water will make it week and not waterproof.

Any joint in concrete must be 100% clean, or the concrete will not bind well enough to be waterproof.

All the above have to be done on a building site in all weather with workers that are not very dependable.''

....So don't rely on it being waterproof. Give that 'task' to another layer. Too much risk, in my view. You're only doing this once!

Posted By: PaulJThe extra cost for the admixtures, waterbars and onsite quality issues probably exceed doing a type C internal drained cavity membrane with sump and pumps, which is recognised as having the lowest risk.

Lucky my basement is open onto a lawn at the front, so water is not really an issue, just damp from the ground on the other three sides.