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Trial pit to check foundations of property

Would a trial hole be needed to check the foundations for an extension on top of the existing structure of the house? What if its not deep enough? The neighbours have extended on top, does this mean its ok?

4 Answers from MyBuilder Extension Builders

Best Answer

Yes you will have to do a trial hole for your own benefit to check the foundations Usually they like to see a metre to metre and a half for foundations depending on the ground the approximately of threes around the foundations And if you are building on top again it needs to be proper Think about yourself never mind the neighbors project👍


Answered 10th Feb 2019

You would need at least one but preferably two. Have you local Building Control Officer check them. If not deep/thick/wide enough then you may need to underpin. Your neighbour having built above is not necessarily a sign that its ok as they may have done that work illegally as happens more often than you'd think.


Answered 7th Feb 2019

Building control will usually ask for 2/3 trial holes to be dug out to determine the depth & width of the founds. They will most likely wish to inspect these also rather than see pictures. If they needs strengthening then additional concrete would need to be specified by an engineer but there is a couple of options they could recommend


Answered 8th Feb 2019

1 hole would be require regardless of neighbours build as could be different ,the hole doesn't need to be big just a shovel by shovel wide. if underpinning needed you don't want that cost on top after you find its sinking ?


Answered 9th Feb 2019

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