Delta-FL Subfloor System

The problem with regular basement flooring
A Delta-FL subfloor system may be a perfect solution for your basement finish job. Most basements are moist and this system keeps moisture from wicking from the basement concrete into your floor. That not only keeps your basement drier which allows for more basement flooring choices, but it also keeps your air quality higher. There are lots of approaches now for keeping moisture (not water, mind you) out of the basement, and this is one that seems reasonable.


Dreams of a finished basement dance in many a homeowner’s head. One of the biggest obstacles to using the bottom half of one’s house is moisture. Earth is damp, even in dry climates, and dampness seeps through concrete walls and floors inexorably. Evaporating dampness keeps the basement cool, often uncomfortably cool. The floor is the worst offender, since residents come into contact with it. Moisture can even creep into the concrete and erode the steel bars and rods. The maintenance costs caused by this are quite high and often force people to take drastic steps to prevent it.


In decades past, remodelers would build a subfloor out of 2 x 4s and plywood, creating an elevated platform to put some distance between concrete and carpet. Unfortunately, this reduced the height of the room by 2-3 inches, and basements aren’t typically very tall to begin with. Worse yet, wood remained in contact with the damp concrete. Inevitably, rot and mold would take over and the basement would acquire an unpleasant smell. Sooner or later, the subfloor would have to be torn up and replaced.


Waterproofing experts turned to plastics around the turn of this century. They needed something that mold would not attack and water could not penetrate. The solution they sought for was something that would not present the problems found in regular basements. It also had to be durable and economical. Many such research programs were undertaken and finally they struck gold. Several types of plastic subfloor systems have evolved. One of them is called Delta-FL.


What is Delta-FL?


Delta-FL is made by Cosella-Dorken Products, Inc., of Beamsville, Ontario. Its purpose is the same as the 2×4 subfloor: to provide an air gap between concrete and the main flooring material. Delta-FL is a mat of high-density polyethylene resin with a dimpled surface. It provides high compression and impact resistance, making Delta-FL very durable. When compared to its plastic counterparts or the old fashioned wooden platform, Delta-FL can last much longer and at a fraction of its cost, when you consider the maintenance and labor charges.


The Delta-FL membrane is installed with its 5/16-inch dimples facing down. Installation is as easy as unrolling a roll of Delta-FL across the floor. The strips of Delta-FL are simply taped together. Then, another subfloor is laid atop the Delta-FL and the main floor covering is attached to it. This second subfloor, or overlayment, might be rubber matting in the case of carpeting or plywood board for linoleum. Floating floors such as laminates or hardwood floors, and even tiles do not require a second subfloor.


Delta-FL- Cost effective


Delta-FL is cheaper than most alternatives and easy to install. If you have a basic understanding of how to install a basement, you can get it done without any external help. This can be a considerable cost saving if you are on a tight budget and need to minimize costs as much as you can. But you must add the cost of the wood upper flooring materials. This cannot be avoided in any cost. However, if you plan your work well in advance, you will have sufficient time to source the raw materials from places where you will get the best price.


DriCore, a competing product, comes in 2×2 foot panels of plywood with dimpled plastic membrane attached, saving one step in the installation process. But DriCore is much more expensive. There are people who prefer it, but a lot of them go with Delta-FL due to its economic prices and high durability.


How does it work?


The makers of Delta-FL say that the air gap created by the mat works by “exploiting the concept of vapor pressure — that is, water vapor seeks to equalize its pressure by moving from areas of high pressure to areas of low pressure.” Warm, dry room air, they say, sucks moisture up out of the concrete. The air gap created by Delta-FL provides a space in which the water vapor pressure in the concrete can equalize with that in the air space, slowing if not halting the seepage of water into the room. Of course, some water ends up evaporating into the room’s air.


The downward-facing dimples are one potential problem with Delta-FL. If a room floods, those dimples will fill with water that cannot be eliminated without taking up all of the basement flooring and subflooring. On the other hand, Delta-FL has no built-in wood components to rot in the case of water damage.


Delta-FL subfloor system is yet another choice for homeowners to make when finishing a basement. It seems best suited for applications that do not require a second, more expensive overlayment.


1 thought on “Delta-FL Subfloor System”

  1. Interesting post here. We’re having a house built up in Pennsylvania, and it’ll have a basement, as most of the houses up there do. I’ll bring this up to our contractor…he seems to be one we have to hover over. I’ll look more into this myself before construction actually starts.


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