Asked on Jan 14, 2012

Temperature for priming/painting a concrete floor?

Evie J
by Evie J
Getting ready to prime (behr masonry/concrete primer) and paint (concrete paint) my basement floor. Instructions say to use when above 50 degrees. Is it possible to do this when it's colder or is this a pretty necessary step? Our basement is heated by space heaters and obviously i'll have those gone to paint the floor. Thanks!
  11 answers
  • 3po3 3po3 on Jan 14, 2012
    I would follow the manufacturer's suggestion. I'd hate to have you waste time and money on this project and have the paint not last. Cold and wet weather messes up the paint and prevent proper adhesion, and shorten the paint lifespan.
  • Will the basement see temps below 50? If the house is heated, the basement temps should not go much below 60 unless the basement is drafty and leaks air. But as Steve said. You need to follow the manufactures directions or you could have issues with it drying etc.
  • Peace Painting Co., Inc. Peace Painting Co., Inc. on Jan 15, 2012
    I believe you will be alright with heaters as long as it is above the 40 degree range. There is some margin with the specifications. The curing process needs a certain amount of time at certain temperatures to allow the 'molecules to coalesce' or interlink. This process will just take longer at a little cooler temps. I believe this can still happen in the 40's, just extend the time between coats and before you get back on the floor. If this were getting outside use, I would be more concerned, but even then your high quality paints like Sher-Will Duration can go through a couple of freeze/thaw cycles before is suffers ill effects. BTW, do you know that you have the minimum amount of moisture migrating through the floor? A good way to tell this is to put down a rubber door mat for 24 hrs. If you see a dark outline when the mat is removed, then you need to rethink the type of material and go to a stain. Damp mop the floor before you start. We put an additive called Emulsabond in the first coat to insure adhesion. I'm not a big fan of Behr, I like to go to a paint store for paint (-; and the primer/finish all-in-one products do everything okay, but nothing real well. But if you have the paint, work with what you have, it will be alright. We are working on a interior concrete floor this week that is peeling up because something was not done right. Follow these instructions and you will do fine. Clear as coffee? Best, Charles
  • Brenda D Brenda D on Jan 15, 2012
    not if the floor remains cold.
  • I agree with BOTH Peace and Brenda. The materials - not the air - is the critical thing to keep track of. If the material ( concrete) is above fifty and the air gets cooler, the only problem is the sheen might not look as good and it will dry slower, meaning possibly several day before walking on it. But if the air is warm and the concrete is below fifty, then you could have a problem with the paint not bonding well
  • Concrete Studio Concrete Studio on Jan 15, 2012
    The most important part of placing color on an slab below grade is the mechanical profiling of the concrete so as to provide an anchor for the coating. Secondly, the fifity degree rule is an absolute; as the viscosity of the coating increases with low surface temperature. High coating viscosity prevents proper penetration for proper anchoring as well as improper coalescing of the coating film. Thirdly, the coating has to be made for use below grade or where high water transmission rates are probable. This requires a transmissive coating. The coating manufacturer you mention is not know, in our field, for having that type of system.
    comment photo
  • Solaris Construction LLC Solaris Construction LLC on Jan 15, 2012
    I'm glad you're including a primer, it's very important. It's also important that your floor is really, really clean. Having said that, I encourage you to look at an epoxy paint/covering for this application. Especially if you're looking for longevity and water resistance from beneath the floor.
  • Concrete Studio Concrete Studio on Jan 16, 2012
    An epoxy coating below grade has to be vapor transmissive or the coating will peel like a wet bandaid. I have never seen a homeowner installed basement coating succeed, as the correct profile is never established. Then, vapor transmission forces will cause the coating to blister or peel. Generally, the peeling is irregular and starts small but the aesthetic appeal of the coating disapears rapidly.
  • since ambient earth temperature is approx 65*f to 68*f, you're above the 50*f level,,, that being said, i've never seen any paint adhere to conc for long,,, you'd be well advised to follow the advice regarding profile & suitable materials - acid-stains & dyes topped w/a good sealer or epoxy,,, the 1st step is ALWAYS to install a moisture test patch to measure rising dampness
  • Peace Painting Co., Inc. Peace Painting Co., Inc. on Feb 04, 2012
    Great to hear from you again C Studio!
  • peach is probably the thread's most knowledgeable for my question - when did behr become a better quality paint ? most pro's i've ever known chose sher-wms, benj moore, or dulux,,, has the orange vest store taken an ownership position in behr & now advertising its purported increase in quality ? ? ? tnxc - enjoy the game !!!!!!!!!!!!!!!!!