When you think of a concrete subfloor, your first thought might be that it’s going to feel cold and hard. So you immediately want to buy a thick, insulating underlay but that’s not always the best type of product to go for.
There are more factors to consider that make buying the best underlay for concrete a little bit more complicated.
As well as potentially being cold and hard, concrete subfloors can also cause moisture which can be problematic for certain types of flooring.
In this blog post we’re going to talk through a number of scenarios which include: laminate, carpet and underfloor heating so you can find the best underlay to suit your needs. We are also going to explain how to check and prep a concrete subfloor ready for new flooring.
Best selling products for laying on concrete
Laying Laminate Underlay on Concrete with Moisture Barrier
Regardless of your subfloor, you always need to use a thin underlay with laminate flooring. But with concrete, it also needs to have a moisture barrier.
This is because concrete subfloors release moisture which can be very damaging if absorbed by the laminate planks.
To prevent the moisture from ever reaching the laminate, you need an underlay with a damp proof membrane.
Laying Carpet Underlay on a Concrete Subfloor
With carpet, there is much more choice as you aren’t limited so much by the thickness and a damp proof membrane isn’t essential.
But there are other factors to consider, such as the room or area of the home that the carpet is being laid.
For low traffic areas such as the bedroom and living room, a thick luxury feeling underlay is a great choice. Our best sellers in this category include:
For high traffic areas such as the stairs and hallway, a cushioning underlay won’t be durable enough and it would also be difficult to fit around the stairs. Our best selling products for the hallway and stairs are the:
These are also great all-rounders if you are looking for a single underlay to use throughout your house.
Underlay for Concrete Subfloor with Underfloor Heating
It is essential that you use the correct underlay with your underfloor heating to feel the true benefits.
A thick, insulating type which would usually help to keep a room warm will actually act as a barrier to the heat from the underfloor heating. This means it will take a lot more time and energy to heat up your room and you might never feel the full effects at all.
Instead, you need a thinner product with a low tog rating. An underlay with a low tog rating will have better thermal conductivity so the heat can easily permeate through the floor and into the room.
Underlay for Laminate with Underfloor Heating
It’s essential to have an extremely thin product with a low tog rating. We recommend the:
Underlay for Carpet with Underfloor Heating
For carpet, you can afford to have something slickly thicker which is great because it will still provide comfort underfoot. Our bestselling product for underfloor heating with carpet is the:
The Duralay King is 8.3mm thick and made from durable sponge rubber so it’s a great choice for anywhere in the home. But the most important factor is the extremely low 0.8 tog rating which will allow the underfloor heating effectively heat up the room.
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How to Prepare a Concrete Subfloor
Whether you are laying carpet or laminate, it is essential that your concrete subfloor is clean, dry and even. Not only will this ensure your new flooring looks the best it can, it will make sure it lasts longer too.
Clean your Subfloor
If your subfloor has old paint, adhesive or wax left over from the previous flooring, it’s best to try and clean this up – especially if your new floor is being installed with adhesive.
You can do this with a scraper and then finish with a heavy duty sander or concrete grinder. If you don’t have one, they are available to rent from most tool hire shops which are easy to find through DoHire.com.
Level your subfloor
For the perfect finish, it’s essential that your concrete subfloor is flat. If not, any imperfections will be visible through your new flooring.
The best way to do this is with a long level and tape measure. It’s recommended that the floor must be uniform within 1/4 inch every 10 feet.
Use a heavy duty sander or a concrete grinder to even out any high spots.
Fill in any low spots with a floor levelling compound and allow it to completely dry before doing anything else.
For a more in-depth guide on how to make sure your concrete subfloor is even, check out this step-by-step guide from Wood Floor Business.
If making your subfloor flat isn’t an option, it is possible to even things out with a felt product such as our Lion 50 Felt Carpet Underlay. The felt will naturally fill in the gaps to create a smoother surface ready for a carpet to be laid. Felt products like this are only suitable for carpets and cannot be used with laminate.
If you are having the same problem and you want to lay laminate flooring, a thick laminate will help to smooth things out.
It is important to check that your concrete is dry before laying any type of flooring, but it is especially important for laminate and wood as moisture is extremely damaging.
If it is a new concrete subfloor, it should be left for at least 30 days before any new flooring is laid.
Use a moisture test kit to test the moisture levels. If they are not within the laminate or wood manufacturer’s guidelines, you will need to reduce the humidity and moisture of the room.
It is, of course, also very important to make sure that your subfloor is structurally sound and fit for purpose.
If you are moving into a new home or you haven’t changed your floor in a good number of years, you might not know the condition of the subfloor.
Check for cracks and crumbling before proceeding to install your new floor.