Advice. Foundations for single story extension near tree.

[paul james]

Would welcome advice re the type of foundations required for minimal impact on cedar tree roots. I have read that screw piling may be an option.
Advice & names of companies that cover the Berkshire area appreciated.

 

[wessex101]

Why are you considering piles? What are you trying to achieve?

If it is to protect the tree are you sure the root protection zone spreads as far as the extension?

If it is to protect the extension from ground movement due to the proximity of the tree the first thing you need to find out is what the ground is. If you are on clay and sit the extension on deep piles you will have to give careful consideration to the foundations to the existing house and potential differential settlement.

 

[^woody^]

Who did the plans? Don't they know how to support their design?

A soil test will tell you what foundations you can have. And building control will need to agree any proposal.

 

[London Mike 49]

When we lived in our last house where we built an extension next to some conifer trees that our neighbor had in his garden ,the BCO made us dig an extra 0.4m of our foundations to counteract any possible movement.
The pine tree that you have in your garden is similar to the conifers in that they tend to be shallow rooted but the roots do spread out and may show in your foundations.
My advice would be to excavate to your architects specifications and let the BCO decide if the foundations need beefing up with extra depth.
Whatever you do, good luck
Mike

 

[tomfe]

My advice would be to excavate to your architects specifications and let the BCO decide if the foundations need beefing up with extra depth.

I would not do this, you would need to get the digger out again and then you are working across already dug trenches.

 

[^woody^]

Drawing says Pine but text says Cedar

No special precautions are needed if more than 6m from a Cedar

 

[paul james]

The council are concerned about the root protection area of tree. Thanks for the advice - I will need a soil test , but from what I already know others im my road have had to use a piling contractor on extensions. The barrier to building are the roots as it has a tree protection order on it.

 

[^woody^]

Its nonsense that roots need protecting. You could pile it and go through a main root just the same, and you wouldn't even know.

No foundations will harm that tree.

 

[wessex101]

The council are concerned about the root protection area of tree. Thanks for the advice - I will need a soil test , but from what I already know others im my road have had to use a piling contractor on extensions. The barrier to building are the roots as it has a tree protection order on it.

Do the calculation for the root protection zone then, the formula is available online if you do a Google search, it is based on the circumference of the tree trunk at chest height or something like that. Generally it is not much wider than the spread of the tree branches for excavations with possibly some temporary fencing and ground protection to prevent compaction of the soil around the tree. Failing that pay for a tree report.