Floor Installation Guide

Have you thought about converting your basement into a more comfortable space? Are you stumped about what to do with the cold uninsulated concrete floor? Insulate the floor cost-effectively with InSoFast insulation panels! InSoFast is an engineered continuous insulation that is easy to install on a cold basement floor.

Optional Floor Prep and Vapor Barriers

In older homes it is good practice to apply a concrete sealer to block moisture or install a vapor barrier on the concrete floor prior to installing the InSoFast panels.
If you have new construction with a vapor barrier already installed underneath the concrete slab, it is not necessary to put another vapor barrier on top of the concrete floor.

Using InSoFast on Both Walls and Floors

Install the InSoFast panels on the wall first. This minimizes the chance of water getting on top of the subflooring in the event the wall leaks.

Installation Methods

There are four basic installation methods: floating, glue down, screwed down, and fully adhered. The floating method is recommended for carpet, laminate, and wood floors. This is a simpler, quicker installation that makes the concrete floor feel softer and more comfortable. The glue down method can be used for carpet, laminate, and wood floors. The screw down method can be used for any flooring type. The fully adhered method is recommended for tiled area to create a solid base that eliminates movement.

Floating Installation

The floating method places the panels directly on the concrete without any adhesive. Interlock the panels together with the tongue and grooved edges in a running bond or staggered pattern.

Glue Down Installation

The glue down method bonds the panels in place with a 3/8″ bead of PL Premium 3X Stronger Construction Adhesive along dove-tailed ribbing of each stud. One 28 oz. tube covers 50 s.f.

Screw Down Installation

Attach InSoFast panels to the concrete floor by installing concrete screws through the studs.

Fully Adhered Installation

For tile applications, the InSoFast panels are set in a bed of thinset tile adhesive with a notched trowel per manufacturer’s instructions.

Interior Partition Walls

Install InSoFast panels up to existing interior partition walls. Non-bearing interior partition walls can be framed directly on top of the subfloor with no need for a treated bottom plate.

Installing Subflooring

Install subflooring with a gap for expansion following per manufacturer’s instructions. Fasten with standard coarse thread all-purpose construction screws. Heavier subfloor panels you may need to predrill a counter sink hole. A pilot hole to allow for the screw to be countersunk a flat-head screw to seat flush with the work surface. Check out the Dewalt Countersik Set.

When panels are installed as a floating floor, it is important to layout the subflooring so that the long seam of the plywood does not line up with the seams in the InSoFast panels. The short seams of the plywood should land over the top of a stud.

Uneven Floors

Prior to installing panels, the low spots can be filled in with concrete patch or concrete floor leveler.
If you notice an area with excessive deflection after the subflooring has been installed, fill the void with adhesive or spray foam. Simply drill a hole through the subflooring and panel down to the void and inject PL Premium Construction Adhesive 3X or gap and crack spray foam. Using too much spray foam will cause a bulge in the floor. Avoid walking on this area until the adhesive or spray foam has set.

InSoFast panels provide a simple, easy way to insulate cold concrete floors. The attachment studs provide a secure surface to screw the subfloor.

Things to Consider

1. InSoFast panels alone can raise the floor by 2 – 2½ inches which will affect any existing door swings as well as the floor-to-ceiling height.
2. A subflooring layer of at least ½-inch will be required overtop the InSoFast panels.
3. Code requires staircase steps to be all the same height to prevent tripping hazards. Measure your final heights accordingly.
4. Water seeks the lowest point in your home. In basement flooring applications, always make sure you have a working sump pump or back flow prevention system to keep sewage from getting trapped in places you don’t want.
5. Double check your local building codes to determine the allowable live load for construction. See the next section on calculating loads for more information

Calculating Loads

You will need to determine what loading (weight per square foot) is acceptable for your local building codes.

For the most part, live load and dead load values for floor systems are considered “distributed loads.” The total weight is distributed or shared uniformly by the members in the floor system. InSoFast panels are uniform because they have 100% contact with the concrete and subflooring.

Our product testing determined that InSoFast panels can support 13 lbs per square inch of compressive resistance at 10% strain deformation. This equates to 1872 lbs per square foot for the design load, well within most residential construction specifications.

Table 3.4 is taken from the U.S. Department of Housing and Urban Development Office of Policy Development and Research’s 

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