A little respect for the underlay

“My wife used to be afraid of the dark . . . then she saw me naked, and now she’s afraid of the light.”

And, “I drink too much, the last time I gave a urine sample it had an olive in it”,  are a couple of classic one-liners by the man who never got respect, Rodney Dangerfield.

So, how does today’s ‘lack of respect’ theme have anything to do with building products, and specifically underlays?

Well, in the residential building biz, homeowners tend to place the utmost of importance on what you see, as opposed to what’s underneath. What you see, or the finished product, is of course important because that’s what you’re going to be waking up to, coming home to, and entertaining guests on, so you want it to look good.

As a result, homeowners tend to splurge the bulk of their budgets on the finished product, while kind of forgetting, or paying little attention to, the seemingly irrelevant underlay, simply because it’s buried.

Underlays are what you place in between the finished floor, and the existing subfloor.

Subfloors may consist of concrete, if we’re dealing with a basement renovation, or plywood, if we’re focusing on any other room in the house. The amount of attention, or money, a homeowner puts towards an underlay, will coincide directly with the basic requirements of the chosen finished floor, and/or on how you expect this finished floor to perform.

Because the subfloor is tied into the structure or framework of the home, you’re basically going to have to accept whatever’s there as your starting point.

So, whether the subfloor consists of concrete, plywood, or in the case of an older home, 1×6 spruce planks, unless you’re prepared to open up the entire joist system, changing or tampering with the subfloor is unlikely.

Therefore, with the subfloor a fixed asset, and the finished floor decided on, it’s important to realize the value of, and give a little respect to, the product that’s going to make or break the long term performance of your finished floor, and that’s the underlay.

Why do we have underlay products? Because in most cases, finished floors aren’t directly compatible with the existing subfloor.

Laminate or engineered floorings, for example, are popular choices for the basement because they’re a good value and easy to care for. However, due to possible moisture issues, wood composites and concrete aren’t good partners.

As a result, laminate floors placed over concrete will minimally require the buffer of a poly (vapor barrier)/ foam underlay. A poly/foam underlay is all you need, and at pennies per square foot, is certainly an affordable must have.

However, there are better choices out there.
Does better cost more? Always.

Poly foams solve any potential moisture issues, but unfortunately will do little to negate the cool dampness one feels when walking on a basement floor. This ‘coolness on the feet’ can be resolved by first installing 2’x2’ Barricade, or DRIcore, underlay panels.

Referred to as sub-floor panels, these floating underlay sheets take the chill out of a basement floor, making life in the basement a whole lot more comfortable.

Barricade is an OSB (oriented strand board) underlay panel with a ridged foam backing, while DRIcore has a plastic dimpled backing. Both do the job, whereby choosing one over the other is entirely based on whether extra R-value, or moisture control, is of greater importance.

Ceramic tile? Même chose, whether it be installed on the wall, or on the floor, you’re going to need an underlay. Tiles being installed in a shower area will absolutely require an impermeable membrane such as Schluter’s Kerdi matting, or Hydraflex sealant, installed over the plywood or mold resistant drywall.

Because floor ceramics require absolute rigidity, cement board or Schluter’s Ditra membrane are your best choices.

Moral to the story? Don’t skimp on the underlay, it’s the key to a long-lasting finish.

Good building.

As published by the Standard-Freeholder
Handyman's Hints Standard-Freeholder Cornwall Ontario by Chris Emard

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