Hi Guys,
Am looking to put a 8 x 4 meter extension on my new build property. I have got the architect drawings done and I’ve gained permitted building rights and planning permission. I have requested building control and currently getting structural calculations done.
I am looking to take the whole back wall out which is 8.7m with cavity. So I am looking to take out 8.1m of the back cavity wall and put a steel across. I understand this will need to be spliced. Is it possible to use a 300x300 beam on engineered pad stones on the 300 non each side?
Also it turns out that the house foundations of the house is 2.2-2.7m deep traditional trench. Do I need to go to this level? Also am being respirated to get a survey done by geotechnical to see what’s down at that depth but this is a crazy amount of money. I can assume that the ground is good as my house is already built. Is it a waste of money to get these surveys done?
In a nutshell 2 questions really?
1. Can I use a sliced 8.1m 300x300 steel on engineered pad stones supported on 300 nib?
2. Depth of footing for extension, do I need to go to house depth and is a survey required?
Thanks in advance.