To reap the maximum utility from your flooring, proper installation is essential. This means the subfloor and the underlayment should complement each other, and prepared thoroughly so that your flooring lasts for generations. Laminate flooring is among the more affordable flooring options and noted for its various advantages. When installed using the proper underlayment, it can last for decades without any major hassles.
This post shares all the information you need about selection and preparation of the subfloor for laminate installation on concrete.
The Challenges Posed by Concrete Subfloor
Different subfloors can pose different challenges and concrete is no exception. When you have a oncrete subfloor the primary problems that arise are:
- Concrete is a porous material and hence are prone to moisture fluctuation
- The adhesives underneath the flooring can loosen when moisture seeps in through the concrete subfloor
- The tiles or planks can warp underneath if a proper underlayment is not used over the concrete subfloor
- Concrete subfloor often has creaks and bumps which may lead to uneven installation of the laminate floorboards, and they may crack eventually and not last long enough.
Preparing the Concrete Subfloor
To minimize the effect of moisture and an uneven surface, preparing the subfloor first is important. You must ensure the subfloor is level, clean, structurally stable and absolutely dry before the next steps of installation are done.
- Before any other preparation, check the humidity level of the concrete subfloor. The humidity level should not be higher than 4.5 percent and if it is, installation of underlayment and flooring over this subfloor can trap the moisture and eventually lead to warping and molding.
Quick tip 1
When you do not have a moisture meter, cut a 2”x 2” plastic and tape it on the floor ensuring it is absolutely sealed. Check for moisture accumulation after 2-3 days.
- Once the moisture level is checked, do the necessary things to reduce the moisture level and ensure it is dry enough for laminate flooring installation. A flooring installation professional can help you out with the necessary suggestions.
- Level the flooring after it is dried enough using a long level and a measuring tape. If there are any high sports, they need to be sanded down using a concrete grinder. Any low points should be filled with a cement-like compound and made uniform enough.
- Lastly, check the concrete slabs for any cracks and fissures as the subfloor must be structurally sound to support the weight of the flooring, furniture and the foot traffic. If there are any cracks and dents, proper repair works must be done first, before you proceed with the installation.
A common myth about laminate flooring is: “Laminate flooring is prone to dents and scratches”.
This is so untrue. In one of our posts we have debunked surprising myths about laminate flooring. Read more.
Types of Underlayment That Are Suitable
Once the subfloor is prepared, a suitable underlayment must be laid over the subfloor before the laminate flooring is laid down. Due to the primary trouble of high moisture, a vapour barrier or an underlayment which have vapour barrier properties should be chosen. The following are some popular choice of underlayment that are chosen for laminate flooring.
- Standard foam barrier
A thin sheet of foam acts as a cushion between the subfloor and the flooring in this case. It is the commonest choice of underlayment for laminate flooring and a chosen option when the subfloor is made of plywood. If it is used over concrete subfloor, a separate vapour barrier must be installed first and then the foam sheet has to be laid. A major advantage of the foam sheet is under feet noise reduction.
- Vinyl backed
This is a standard choice of underlayment for laminate flooring if you need noise cancellation properties. These come in easy-to-install tile form which lays flat once it is installed. For moisture proofing it further, the seams have to be sealed thoroughly. It is a practical choice of subfloor that is preferred by many homeowners who are looking for noise and moisture proofing the floor.
This is an underlayment similar to the standard foam barrier but has an additional layer of moisture barrier attached to it. If your home has a higher moisture level, and concrete subfloor, this is the best option to invest in. moreover, when you are installing laminate flooring in the basement, the chances of moisture damage is higher. The combination underlayment works best in this situation. It is slightly more expensive compared to the standard foam, but the expense is worth it since your laminate flooring will last much longer withstanding the high moisture.
- Padded laminates
These days, there are laminate flooring tiles or boards which come with in-built padding underneath. Opting for these tiles mean you do not need to additionally invest in an underlayment though many prefer to choose a vapour barrier seal in addition to the padding so that the tiles are better protected.
If noise reduction is the main priority, cork is the best choice of underlayment that can be used with laminate flooring. It is also one of the most expensive underlayment options because it is a natural material with antimicrobial properties. However, when used with concrete subfloor, a proper vapour barrier or moisture sealant will be needed. Altogether, the overall cost of installation can go up to 50 percent of the laminate flooring material cost, and this may not be feasible for many buyers.
Choosing the right underlayment for installing laminate flooring is important to maximize its life-span. There is a common misconception that concrete subfloor is a good option because of its hardness and many forget about its porous nature and eventual trouble with seeping moisture. Keeping the above-mentioned tips and products in mind will help you to find the best solutions against moisture trouble posed by concrete subfloor.