Sealing a Concrete Floor
Q: We purchased a home that had carpeting in all the bathrooms. We did not like this so we tore out the carpeting in our upstairs bathroom and installed vinyl linoleum. We decided to do our downstairs bathroom.
After pulling up the carpeting we found there was a linoleum flooring under the carpeting. We found the toilet had been leaking and the concrete flooring was damp. We did not seal the concrete flooring before installing the new linoleum and now it has terrible staining all around the edges of the new floor. What should be done to seal moisture from coming through the new linoleum?
A: This problem may result from something often overlooked by flooring contractors. The herkle ring (the pipe that comes up through the floor that the toilet mounts to) needs to be sealed because this area between the floor and the pipe is a passage for moisture. A high quality, flexible silicone sealant, applied around the ring, should help keep the vapor emissions down. In the past these pipes were cast iron, but are usually plastic now. People often blame leaks on the wax seal directly under the toilet when the problem is actually this gap between the pipe and the flooring material.
Seal the herkle ring, then put on a new wax ring, (always buy the highest quality--not a discount one), and follow the instructions. The wax ring is applied to the toilet first, not to the herkle ring. Set the stool and tighten the nuts by going from one to the other. Don't tighten one side down firmly and then go to the other because this could cause your fixture to lean to one side, or worse, crack.
Flooring installers check the moisture level of concrete at the time of installation. If the levels are suitable at that time, flooring may be installed. If something were to change (i.e. heavy rains after a long drought season, changing landscaping and providing inadequate drainage, or any other related actions) the home may be subject to vapor emission.
You may have even had significant emissions you were unaware of prior to changing the flooring because carpet is porous and absorbs more than vinyl, which is nonporous and traps moisture underneath it.
When installing vinyl in a high moisture area, dry the floor first; this may take several days to weeks. Purchase a vinyl with built-in mildicides that won't allow mold growth. Buy an adhesive that has a sealant built in, making sure it is compatible to the flooring. If your concrete floor is too damp, consider other flooring options, like tile.
You'll usually get the best results from tearing up an existing floor before installing new (and most flooring manufacturers will not honor warranties on material installed over old flooring). However, there are times when it is advisable, for example, to encapsulate old flooring containing asbestos or to add an extra level of moisture protection. Since your neighbors have had the same problem, it would probably be a good idea to have someone come evaluate your specific situation first hand.
To talk to some local specialists to determine the moisture level of your concrete or help you decide whether to remove the flooring or install a new layer over the top of it, visit Home Advisor. Fill out a service request and be matched with the ideal service professional in your area.
-- Tips courtesy of HomeAdvisor.com