Ground floor joists

[marky1]

Hi all,

Firstly hello everyone, I've spent a fair bit of time reading through the posts on your site and picked up some useful info!
I've got a question myself now and was hoping someone might be able to offer some advice?
We have a bungalow which we are planning to extend and convert with 2 bedrooms in the loft. For the extension, we plan to use suspended timber floor as is currently in the existing ground floor. The extension is just over 2 metres out and runs the entire width of the bungalow ( 9 metres ). The joists in the existing floor run Side to side. My question is, would it be normal practice to run the new ground floor joists to the shorter span or would it be better practice to run them the same way as the existing joists which would obviously require some additional support?
Any advice will be gratefully received!
Thanks
Mark

 

[dilalio]

What's the reason for going with a suspended floor? Most extensions involve a concrete slab with dpm insulation and screed.

 

[^woody^]

Joists invariably span the shortest distance.

Design should be based on modern, economic and practical methods. A suspended timber ground floor would not normally be used just because there is one there already.

 

[dilalio]

Block and beam would be more likely to be used if site levels mean you're way up out of the ground!

 

[marky1]

Thanks for the replys all. The site is sloped, meaning the finished floor is a good couple of feet above the ground level. Initially the architect did suggest block and beam, however when we discussed underfloor heating the ground floor it was decided it would not be practical to have what will be half the kitchen timber floor and half block and beam.
We had the plans drawn by an architect and approved a couple of years ago now, and had estimates at the time for the works to be completed by local builders. Unfortunately they were coming back a little above our budget, hence the delay whilst we saved a bit more. Now we're in a position to get started, our chosen builder has pointed out the lack of detail in the plans for the ground floor construction. Ultimately I think I will end up going back to the architect to get the detail confirmed on the plans. However I do appreciate the voices of experience that you folks are able to offer before I go back and try and resurrect his interest in our project!
Based on the reasoning behind continuing suspended timber into the extension. Does it make any more sense now? I'm more than open to any ideas that would seem more sensible.
Looking forward to your opinions!
Thanks
Mark