Brits love carpets. In fact, between 2008 and 2021 we collectively spent £764 million on them! While a home’s floors are often thought of as merely the top layer that we walk on, it goes deeper than that, literally! A floor is a layered system of essential components that work together to allow your chosen flooring on the surface to do its job.
One that is pivotal to functional and long-lasting flooring – and yet is seldom seen – is the underlay. In this guide, we’re going to be talking about carpets specifically as we answer this frequently asked question: what’s the best carpet underlay?
What is carpet underlay?
Before we get to our central question, let’s lay out the fundamentals, beginning with what carpet underlay is actually comprised of.
Carpet underlay is an essential part of any carpet replacement as it will ensure your new carpet lasts its lifetime. In simple terms, carpet underlay is the layer of material that sits between the carpet and the subfloor, acting as a protective blanket. Because underlay is a catch-all term, it will take different forms depending on the flooring material it supports, in addition to the type of subfloor you are working on.
When does it need replacing?
When you go for a carpet refresh, it’s tempting to leave the existing stuff where it is. After all, carpets are pricey – we don’t deny it. However, there are many compelling reasons to put down new underlay with a new carpet.
For example, are you aware that a high-quality underlay will not only prolong the life of your new carpet by cushioning the impact, but will also help insulate the home? So while you might knock a bit off your initial carpet fitting costs, it won’t be anywhere near as cost-effective in the long run.
Here’s a bit of advice from the experts: if you’ve had your underlay down for yonks, or you don’t know how long it’s been since the previous owner of your home had it fitted, it’s time to replace it. We go into more detail in our DIY underlay fitting guide, but for the best results, make sure you’re laying it on a nice clean, dry and level subfloor. With a professional fitting and the best type of carpet underlay for the job, you can expect it to last up to 25 years.
Underlayment basics: why is underlay important for your carpet?
Carpet underlayment is the foundation of any good carpet fitting job. Unlike the subfloor, which makes up part of the building’s framework and structure, the underlay functions to create a flat, smooth surface that will allow for a straightforward and seamless carpet installation.
It adds a much more cushioned depth of comfort underfoot than carpets without underlay or old worn-out stuff. And, again, its insulating properties are not to be taken lightly either in the wake of rising energy prices – don’t forget about sound deadening too!
Types of carpet underlay
Exploring which carpet underlay is best for your personal scenario is essential for a high-quality job. The right material can increase your level of comfort and give your carpet’s lifespan a boost of up to 50%. We use these types of carpet underlay for our fittings, so these have the Derwenthorpe seal of approval.
PU (polyurethane)
Now the most popular due to its availability and competitive pricing, polyurethane (colloquially known as “PU”) has overtaken rubber in the market. It is generally made from recycled foam offcuts, so is slightly better for the environment than virgin varieties. With thicknesses starting from 7mm to 12mm, it will cater to all types of floors and you’re sure to find some that will suit your budget.
Rubber (rubber sponge)
Once the leader of the carpet underlay industry, but still sold globally, rubber is much heavier than PU and often more expensive. Although it is now made from synthetic rather than natural rubber, there’s no loss in quality and you can find it in a variety of thickness levels. With a great spring retention and a super spongy feel underfoot, this is a great option if you prefer a luxuriously soft carpet.
Crumb rubber
Usually used in areas of heavy footfall and is perfect for pubs, hotels and offices. That’s not to say it wouldn’t perform excellently in your home though. Crumb rubber is a dense and durable material that is bound to protect the carpet at the surface. While not the comfiest underfoot, it does well in the arena of sound and heat insulation around the home.
Combination
Combination underlay features a crumb rubber base with a felt top. Perfect for wool carpets and those big rooms that require seaming, it is nearly always made from recycled materials ensuring your carpet is not only going to last, but you’re doing your bit for the planet.
Carpet underlay versus hard floor underlay – is there a difference?
The short answer is yes, although you could be forgiven for believing that underlay is underlay, and will work underneath any surface flooring. The unfortunate truth is that not all underlay is made equal. In fact, there is even variation between different types of carpet underlay, depending on the intended application.
As a rule of thumb, carpet underlay is designed to be yielding and comfy as you traverse it, whereas underlay for hard floors such as LVT and vinyl primarily functions to aid floor adhesion and provide a protective moisture barrier between subfloor and flooring.
Laminate
There are many options to mull over starting from 2mm thick, but generally, there’s no need to go above 5mm thick. This underlay needs to be dense because any movement underneath the laminate will result in your flooring failing. Before putting down the flooring, your installer should check your subfloor for moisture and advise which underlay is suitable.
Luxury vinyl tile
Only a few different options are readily available for this type of flooring. You can get some that act as a base layer that you can glue directly onto, but there is also the option to purchase a product with an adhesive top that the tiles will adhere to – think of it a bit like a giant sticker. Be careful where you fit this type of underlay as it is a loose lay system and will expand if left in direct sunlight, causing your floor to potentially fail.
7 considerations for careful shoppers
We’ve answered the question “what’s the best carpet underlay” in theory, but it’s far more likely that your choice will hinge upon the following considerations as you weigh up your personal preferences with the required underlay conditions for the job.
Here are 7 questions to ask yourself during the decision process.
1. What is the style of carpet you’re placing on top?
The type of carpet you have fitted on the surface won’t have a huge impact on which types of carpet underlay are best for the job. However, if you’ve chosen a thinner carpet, it might be a good idea to opt for a higher tog underlay for that extra comfort and thickness.
Another thing to consider if you’re installing a wool carpet in bedrooms, hallways or stairwells, for instance, is opting for a combination or felt underlay as it will provide that soft, pliant feel under your feet whilst stopping the wool from flattening out.
2. What type of subfloor will it sit on?
Working out which carpet underlay is best for you will likely involve thinking about the subfloor you will be placing it on. Will it be going on top of a concrete subfloor? Perhaps sponge rubber underlay is the best option for you. After all, it provides high levels of shock absorbency, sound-proofing and insulation on that cold, hard subfloor.
3. Where are you placing your new carpet?
The area that is being carpeted will need to be factored into your decision too. Heavy-use areas such as a home office will need a different type of underlay, usually requiring a thinner and much more dense material, which could take the weight and movement of an office chair for example. This type of underlay would also need what is called a double-stick installation.
4. How important is comfort underfoot?
Do you like an extra soft and spongey carpet? Then maybe it’s worth shelling out a little extra money to get that ideal sensation when walking across the room. If this isn’t a major concern, then you might want to opt for a slightly thinner budget option to shave a little off the overall price tag.
5. What sort of longevity are you aiming for?
As we mentioned briefly in this article, carpet underlay typically lasts for an average of 25 years’ worth of wear and tear. Often you will find that crumb rubber underlay out-performs other types in terms of durability, but you can also opt for higher levels of thickness to ensure that your carpet lasts as long as possible.
6. Are you looking for a decent carpet warranty?
If you’re still toying with the idea of going new carpet, old underlay, here’s a word of caution. Many manufacturers’ warranties will be invalidated if new underlay is not fitted with the carpet, so if you want to
7. What is your budget?
This is an obvious one, but when faced with a fresh carpet, it’s easy to get carried away and gloss over how much the underlay costs as part of the fitting. Before you make any commitments make sure you’re happy to part with the amount it costs, so you don’t feel any lingering regrets later down the line.
Finding the best carpet underlay for your needs
So to conclude, there are no hard and fast rules when it comes to picking out an underlay for your new carpet, and no one simple answer to the question “what’s the best carpet underlay?”
Really, the question should be “what’s the best carpet underlay for me?” Weigh up our suggestions along with your individual requirements and you can’t go wrong.
Still uncertain?
Phew! We just covered a lot of information on the types of carpet underlay on the market. Hopefully, by now you have a clearer idea about what you’ll need for your own projects, but if you’re still feeling uncertain about it, we’ll happily talk you through your options.
To find out more about the underlays we stock or to discuss your carpet fitting needs, don’t hesitate to get in touch.
