Robert Lamoureux: Mold and leaks around new windows

Robert Lamoureux
Robert Lamoureux

Question No. 1 


The photo shows that this is the job going on right now at my son’s house in Texas. They are replacing a failed window and they are going to fill this gap at the top of the arch with caulk. What do you think? 

David R. 

According to contracting expert Robert Lamoureux, the reason that mold will continue to grow despite window removal is there is an active leak somewhere, providing the necessary moisture for mold spores to grow and spread. The gap left in this reader-provided photo is too large to be filled with any kind of caulk or sealer. Courtesy photo

Answer No. 1 


No, this is absolutely not a proper installation. Have them stop immediately and do it right. This gap is too large for any type of caulking or sealer. This must be framed in properly. To seal that sized gap with some type of sealant will only cause future leaking. Maintenance to this area would be needed annually — most likely redoing dried/failed caulking. At this point the window needs to be removed and the framing redone to fit the window size properly, so that the gaps are closed all the way around, as per specs. Once the window is properly framed, then and only then is the time to add any type of sealant, for minor air gaps. Always follow manufacturer specs though, for their guarantee. Good luck to your son. 


Question No. 2 


I rent a home and there are ongoing mold issues. The mold reappears continually, and the landlord is saying that it is our issue and not his responsibility. This is an exterior wall adjacent to the bathroom, and I don’t feel moisture from the drywall but do see mold. No matter how much I “clean it up,” it comes back and is now covering an area about 7 by 3 feet. I cannot figure out why the mold would reappear after being removed. Do you have any insight? 

Chad H. 

Answer No. 2 


The reason that mold will continue to grow despite removal is that there is an active leak somewhere, providing the necessary moisture for mold spores to grow and spread. This is what I refer to as “the perfect storm” for a mold situation. You’ve got nearby water source (bathroom), an exterior wall, which is generally cold conditions, and behind the drywall is a nice, dark area where the mold can grow well, given all conditions. Being that you are a tenant and not an owner, this will need to be done through the owner and it is clearly an owner responsibility. Now that there is mold in this size area, the owner will need to have a mold abatement company come in and remove it under proper conditions for safety. They’ll come in and set up necessary containment tenting, they’ll remove all materials containing mold and they’ll scrub affected timbers with a germicide. Following, they’ll set air scrubbers within the containment, which will need to run for 24 hours, and only then can testing be done. A third-party testing agent needs to be called in. They’ll take samples and an independent lab will test, to ensure that no mold has remained. Once there is clearance, this is when the plumbing repairs must happen. If the leak source is not clear now that the drywall is opened, the owner may need a leak detection company to come in and figure out where the failure is. At that time leak source repairs can be made, followed by closing up the drywall and all final aesthetic repairs can be completed. It sounds like your first challenge will be to get the owner to take responsibility. My best advice would be to make all communications in writing, so you have a paper trail of communications and requests. Sometimes that is enough to encourage people to do the right thing. I recommend mentioning how fast mold can grow, and that the costs also grow with the size of the affected area. The sooner he/she takes action, the less money it will cost for mold abatement. Good luck to you.


Related To This Story

Latest NEWS