Thursday 13 January 2011

Building an extension.....read this first

Inspection Advice Notes for Building Owners and Builders





Extensions/New Build





Prior notice should be given to the Approved Inspector or Local Authority before commencing work, the 1st inspection will usually be when the excavation is ready for inspection. It is advised at this stage to discuss with the Building Inspector the stages when you should give notice before covering up. Stages to be notified would normally include commencement,excavation,damp-proof course,oversite,drains,pre-plaster(No notice required) and completion.



Foundations





Foundations will be inspected, prior to inspection the excavation should be made ready, for a standard strip footing it would be prudent to note the following however if the ground is bad a Engineered solution may be required.







Excavation depth in clay to be min 900mm and to invert of basements or any drains within 1m

Excavation depth in clay will also be dependant on nearby trees. Guidance can be found from NHBC tree tables or similar

Excavation depth in sandy or granular soils to be min 750mm deep

Foundation concrete to be generally min 600mm wide and 150mm thick for cavity wall

Drains passing foundation trenches to be protected from foundation concrete and masonry

Existing foundations to be checked for suitability of any increased loads

Existing foundations should not be undermined

If poor ground is encountered or any thing that you are not sure of discuss the issue with your Building Inspector or Structural Engineer

Excavations can collapse and care should be taken

for more details and advice on this see http://www.buildindbuilding.co.uk/ 





 
 
 
 
 
 
 
 
 
 
 
 
 
 

1 comment:

  1. Thanks for sharing your very thoughtful information regarding proper building guidelines. Those you have mentioned were very important considerations that home owners must bare in mind, building a home or building is not just as simple as constructing the building alone, it's a matter of proper guidelines and specifications as well.

    ReplyDelete