We have a H or P block and a MASSIVE old fig tree in the corner the block is about 2000sqm and are concerned about the roots of the fig tree, what do you suggest we do to make sure the slab stays where it is?
Hi Annette,
Firstly apologies for the delay in responding. The truth is I had to do a little research by asking some close colleagues their opinions before responding.
I think up front I have to say that this is one of those jobs that requires the input of a qualified engineer. If you entered into a building program without the input of an engineer you are certainly heading for problems down the track.
There are a couple of approaches available, namely:
• If the proposed building is to be of a timber framed construction I would employ the use of screw piers/piles to get to a stable layer of soil. This will remove the possibility of movement of the reactive soils and also allow adjustment at a later date. The adjustment of the piers/piles will also enable a degree of flexibility to counteract the action of any tree roots.
• If the building is to be a brick cavity or brick veneer on a slab I would probably use a waffle slab on piers/piles for the same reason stated above.
With regards to the introduction of barriers to prevent damage to the building from the invasion of the tree roots, there are systems available, but I honestly believe that this type of tree will eventually grow over, under or around such a barrier. Hence my comment to get an engineer to look at the site to come up with a solution.
I hope this is of use to you.
Kind regards,
Mike