With the subject on the table being basement floors, let’s continue with our discussion regarding basement subfloors.
A basement floor, regardless of your choice of finishing materials, will always be better with a subfloor underneath.
Basically, the basement subfloor serves three purposes. One, it adds thermal value, deflecting the dampness of the concrete, while creating a warmer walking surface. Two, subfloors cushion what is a totally unforgivable concrete floor, creating a more comfortable surface to walk or play on. And three, the dimpled or foam underlay membranes will negate the effects of a mild to medium water infiltration issue.
Essentially, the basement floor experience is similar to rooting for a Canadian-based hockey team as it jostles for a playoff position. Eventually, they will disappoint us.
If you’re a Habs fan, this means brooding through the month of February, waiting for that elusive blockbuster trade that’ll either boost us into contention, or bury us in the league’s basement, all while a team like the Arizona Coyotes – where the average citizen of Glendale couldn’t distinguish a hockey puck from a stale bagel – still manages to be blessed with a team in playoff contention.
If you’re the owner of a just-renovated basement space, disappointment will usually arrive during the spring thaw, where foundation walls with a perfectly dry history, somehow and by some ill fate, develop a few cracks, with this breach leading to a puddle in the games room just deep enough to bury the soles of your slippers.
However, if there’s an underlay in position, mild flooding will effectively stream through the dimpled underlay membrane, making its way to a floor drain or sump pump well located in the service room.
Last week we talked about the dimpled membrane/ridged foam/plywood strategy, or basically what is the ultimate in basement floor underlays, due to this system providing a deeper air space to accommodate any moisture issues, along with a superior thermal value, providing a warmer floor surface. Another bonus to this three-ply system is that the rolled dimpled membrane, and 4’x8’-sized foam and plywood sheeting, effectively conform to any slight dips or irregularities in the concrete floor.
If you’re considering the dimpled/foam/plywood option, be sure to choose Dorken’s Delta floor dimpled membrane, which is grey in colour, and avoid saving a few bucks by opting for a dimpled foundation membrane, which is usually black.
Besides the difference in colour, the floor and foundation membranes are identical, which may entice homeowners to go with the cheaper foundation product. However, the Delta floor product is made with virgin PVC material, with this pure material format eliminating the VOC (volatile organic compound) element.
Foundation dimpled membranes are meant to be buried in the soil, and as a result are the recycled by-products of anything from gas “jerry” cans to toxic waste containers.
So, and because suffering stomach or headache issues due to the off-gassing of such a product, especially after your basement’s finally completed, would certainly be lousy, with the $50 saved offering little comfort at this point, stick with a proper flooring membrane.
However terrific, the three-ply system may constrict your available headroom, eating up about two inches of floor-to-ceiling space. So, if a two-inch thick subfloor is going to bring the taller people in your home perilously close to the ceiling’s ductwork, you may want to consider an alternative subfloor system such as Barricade’s foam-based subfloor panel (R3.2 value), or Barricade’s Dricore air-plus, with a plastic dimpled bottom (R1.7 value).
The advantages to the Barricade products is they come in a one-inch thick, all-in-one (plywood and membrane combined) 2’x2’-sized sheet, which is certainly easier to carry down basement stairs than full-sized sheets of foam and plywood. Plus, these Barricade sheets require no nailing or screwing down into the concrete, and simply fit tight together (no glue required) with the aid of a mallet and tapping block.
Next week, more on basement flooring.