timber frame raft foundation

sully123

im putting on a small extension to the side of my house, about 1.5m x 8m, single story with slate roof. its in timber frame with no block work on the exterior.
does anyone have any suggestions about the size of raft foundation needed?

im gonna make the main slab 150mm thick with mesh reinforcement.
im not gonna make a step at the edge.

now if the perimeter of the raft is usually 600 wide 600 deep for a standard 2 storey house. considering the light weight construction of my small extension what size would be sufficient?

thanks

AckwelFoley

sully123 wrote: »

im putting on a small extension to the side of my house, about 1.5m x 8m, single story with slate roof. its in timber frame with no block work on the exterior.
does anyone have any suggestions about the size of raft foundation needed?

im gonna make the main slab 150mm thick with mesh reinforcement.
im not gonna make a step at the edge.

now if the perimeter of the raft is usually 600 wide 600 deep for a standard 2 storey house. considering the light weight construction of my small extension what size would be sufficient?

thanks

Im not certain, but im pretty sure we cant advise you on this due to forum rules.

I would advise that you do get someprofessional advise on what type of raft is required for this specific construction as i think its a bad idea to used best guess on a foundation

Carlow52

+1 with Snyper.
In addition from here
http://www.iaosb.com/html/foundations_.html

see this
Raft Foundation, is when concrete is poured over the whole area of the house making it look like a big slab and strong enough to carry the total weight of the structure. Raft foundations require special design and construction and should only be considered if it is done by special contractors and supervised fully by your qualified engineer or architect.

If I was doing this job my big concern would be settlement versus the current house so given that the TF will sit on a block or 2 on flat I would build a good decent foundation, deep enough to be below the frost line and allowing for poor ground and get on with it.

To be blunt about it, saving a few shillings on concrete and excavations now will only be a down payment on loads of heartache later

Joey the lips

Ask a mod to transfere this over to construction you might get more advice.

http://www.boards.ie/vbulletin/forumdisplay.php?f=876

Martron

there is always rule of thumb advice that would work adequtely well but i think that if you were to attach it to your house you would want to seak professional advice.

there could be further implications like house insurance etc etc if anything would to happen you may not be fully covered

delly

Thread moved to construction forum

Poor Uncle Tom

Our charter does not allow us to specify structural elements.

Get professional advice from an Architect/AT/Engineer.