While Installing a Cabinet the Back Came Off
This is a very frustrating situation when installing a cabinet and the wall has a hump in it. Sometimes the back will have a tendency to come off when you tighten the screws down. It may not separate from the cupboard sides entirely, but instead just pull away enough to be noticeable.
There are a few options available in relation to how you handle this frustrating situation.
1) Remove the installed cabinet and repair the damage
2) Leave the cupboard in place and caulk the gap on the inside
3 )Loosen the installation screws, while leaving the cabinet in place using clamps to fasten it to the surrounding cabinetry. Wedge shims between the wall and the cabinet back, forcing the gap to be lessoned. Leave the shims in place and re-install the screws.
All cabinets are made differently. Therefore, some structural designs will have better strength in holding together when there are humps in the walls that create void areas behind the cabinets. For instance, if your cabinet’s back is made out or one half inch thick material it will have good holding strength. But if the back is only made of one eight inch thick board it may pull away from the other cabinet parts rather easily.
One way to avoid having this happen at all is to make sure that you are aware of the void and fill the area with a shim before you lock the cabinet into place with the installation screws. If you will do this there will be no room for the cabinet back to pull away while installing it to the wall.