Now that all of the inspections have been passed, you can backfill most of the property this may seem simple enough. However, it is a very crucial process that must be completed correctly in order to avoid major problems.
We discussed the concrete needing time to cure earlier and this is especially important for any tall unsupported walls. Some engineers will specify that the main floor deck must be installed before backfill to provide support at the top of the wall ( this is for full height concrete walls ). However it will be difficult to have the framer do this ( they would prefer to start work once backfill has been completed ).
I recommend to partial backfill over any areas of concern in order to keep the project moving ie. over a 30′ long wall that is in a straight run you would only backfill 5′ in the centre area and slope back up to the edges where there is support. This will prevent cracking on the wall, and once the main floor deck ties it in place and the concrete has had longer to cure then it can be fully backfilled, either by machine, slinger or even hand if necessary.
It is essential to have someone skilled watch the excavator operator while backfilling, the poly needs to be removed, any debris also needs to be moved out of the way, the machine can not get too close to the foundation ( a full size excavator weighs 40,000 lbs and if it gets too close to the new foundation walls can easily crack them ). It will often be appropriate to backfill with a smaller machine in some or all areas ( watch your contractor closely since its cheaper for them to do it all with the same machine).
Its also critical to watch for large boulders falling against the walls as these can crack the foundation as well as damage the drainage system. Any pipes hanging against the foundation should be bedded with fill ( by hand ) as the backfilling progresses, the hangers are only so strong and if they break off the pipes will not have proper grade and is expensive to fix once the house is complete.
If there is window wells needing to be built then these should not be backfilled fully either, a footing on solid bearing or proper re bar dowelled in to the foundation at different angles is essential for these to be solid and stable ( it looks terrible if these start to fall away from the foundation and is very difficulty to fix ).
Leave A Comment