I posted this over in the Bathrooms forum, but not sure of the most appropriate location.
I have a 6 foot one-piece Lasco fiberglass tub/shower/whirlpool that was installed in my home 2 years ago. It was not set in concrete or otherwise provided with extra bottom support, and has developed 2 cracks along the sides which appear to have been due to the flexing of the bottom of the tub.
I've had the cracks repaired under warranty by a fiberglass repair company, but I am concerned that they will recur or that new cracks will form since the bottom of the tub does flex when you walk on it.
The fiberglass repair folks told me that they always set tubs in concrete to prevent the bottom from flexing and cracks from occuring. The builder claims that the tub was installed according to manufacturer instructions (I'll have to research this) and is therefore refusing to do anything additional.
Is this something about which I should be concerned, or were the cracks likely an unusual occurance?