Question: Hi Robert, we are adding Granny quarters to our property in the Santa Clarita Valley and are putting tile floors in. Two different contractors have given bids and one of the bids stated that we need to put an anti-crack membrane down and this, of course, increased the cost of that bid.
We’ve just received both bids and wanted to have you weigh in prior to making any decisions or even inquiring about this with that contractor, so that we aren’t taken advantage of. We don’t want to be skeptical about contractors but have heard so many horror stories that we just feel the need to be knowledgeable prior to speaking with him. Is this necessary or just an unnecessary upsell?
— Leah and John F.
Answer: Leah and John, the anti-crack membrane is not mandatory, but I highly recommend it. When on a concrete slab, you hope that the slab is thick enough and the earth below that compacted enough to never have enough movement to crack the foundation.
We do, however, live in earthquake territory and cracks can sometimes happen. This anti-crack membrane separates the concrete slab from the thin set that tile is installed with, so they essentially become two separate areas.
If the slab experiences any cracks, the membrane prevents that crack from transferring to the thin set and ultimately, to the tile. The cost is higher, but if you can squeeze it into the budget, it will definitely be a nice feature to help prevent the possibility of crack transfers, over the years. The cost of tile repair later on will outweigh doing it right in the beginning. I hope this helps, best of luck.
Robert Lamoureux has more than 40 years of experience as a general contractor, with separate licenses in electrical and plumbing contracting. He owns IMS Construction Inc. in Valencia. His opinions are his own, not necessarily those of The Signal. Opinions expressed in this column are not meant to replace the recommendations of a qualified contractor after that contractor has made a thorough visual inspection. Email questions to Robert at [email protected].