As a professional wood floor installer of over 15 years, I’ve got some strong opinions about different sub-floor materials. Two sub-floor types that I see often are Plyboard and Chipboard. In this article I’ll be looking at both and giving you some insight as to which one is the best..
We will be comparing the like for like cost per square metre, the usability, durability, quality and finally I’ll be summarizing what I think of these too products to hopefully give you a clearer picture while you’re considering an adequate material for your sub-floor.
Like for like cost
Let’s look at the cost per square metre between 18 mm thick structural plyboard and moisture resistant treated tongue and groove chipboard. I’ll be basing this on 18 mm thickness sheets as this is the minimal ideal requirement for sub-floor materials.
Structural Plyboard – A sheet of 18 mm x 1220 mm width x 2440 mm length, currently at around £28.85 per sheet (Please note, square cut ply may require support noggins along the edge of the ply from joist to joist. Tongue & Groove ply will not require support noggins at these points). This gives a price of £9.69 per square metre. Amendment (24th March 2014) in relation to current improvements in sub-floor ply. Certain issues with cheaper standard ply has lead to the creation of sp101 plyboard which is fast becoming the recognized choice within the industry for acceptable sub-floor ply. This has been developed in recognition of blurred lines with regards cross use of different plywood products and given a definitive particular sub-floor plywood product.
Treated Chipboard – A sheet of 18 mm thick x 600 mm width x 2400 mm length, currently at around £9.32 per sheet. This gives a price of £6.47 per square metre.
WOW! Has your mind just been made up? Well, I urge you to wait a couple of more minutes and read the rest of this comparison. There’s good reason for this price difference and you should be fully aware of this on a practical level before you go clicking that button.
You’ll find the usability of both these sheet products very similar although the plyboard has square edges and the chipboard often comes with a machined tongue and grooved (T & G) edge for each sheet to interlock. They both cut relatively easily although I find the chipboard gives a far finer dust. I’d always certainly recommend wearing a mask when cutting either.
Plyboard is essentially several thin real wood veneer sheets glued together and can often splinter slightly on one side while cutting, however, I would not consider this an issue as we are talking about a sub-floor product that will be covered and rarely chips to the point that it would lose it’s integrity. When handling plyboard, if you’re not careful it tends to be much easier to get a splinter stuck in ones hand than with chipboard although working with both materials can leave cuts and splinters if care isn’t used when handling them.
On the grand scale of things there really isn’t a huge difference between the weight of each. Often the range of sizes tends to be better with chipboard as it’s manufactured for the purposes of a sub-floor material and often comes in 600 mm width for ease of maneuvering within a home environment and general handling, whereas plyboard is produced as a multi purpose material hence often comes in larger set sheets.
When installing chipboard, as mentioned, it is often machined with a T & G edge. This means it is installed by slotting together each sheet. When installing chipboard in this manner it’s always worth checking each T & G to make sure that no poorly machined tongues or grooves will obstruct the sheets fitting together. Damage is easily caused to the edges during transport and should also be checked for, as again any crushed parts of the T & G can cause obstructions. Damage rarely happens to plyboard as it is a solid sheet material with no fine edges to damage and does not lock into itself as with chipboard, so any minor damage is often not a huge issue. For this reason alone plyboard is much faster to install.
From past experience I have always found plyboard to be the most hardy of the two materials. Even with chipboard that has been treated to resist moisture, it will often still swell, eventually rot and become weak after constant contact with water. I have always found that plyboard is far more resilient to water for a longer period of exposure and doesn’t lose it’s structural integrity compared to chipboard. Don’t get me wrong, they’re both wood based products and whether they’re treated or not , given enough water, both will still often require replacing.
Chipboard seems to sag between the joists. In my travels I have noted this on many occasions. Very rarely have I seen the same happen to plyboard. Due to chipboard being made with compressed wood chips, it doesn’t have the same core strength as plyboard. When I go to look at an installation where I’m installing a wood floor on top of chipboard, I see the sagging phenomenon an unacceptable amount and find myself advising customers to either remove the chipboard or look at ways to strengthen it. Have a guess what material I advice to strengthen the chipboard, yep, plyboard.
I judge quality of a sub-floor on several factors. Strength, longevity and sound.
It’s clear to me that plyboard is by far the strongest of the two products. To give a clear comparison, when installing a solid wood floor directly to a sub-floor, It’s a widely recognised fact that the secret nailing method cannot be used when installing on top of chipboard as it isn’t made from a strong enough material to allow the fixing nails to hold. Plyboard has more than enough core strength to hold fixing nails.
Plyboard certainly has longevity. It doesn’t tend to sag and, as mentioned, will often deal with water far better than chipboard. Although replacement of both material may be required if subjected to too much water, I have always found plyboard to keep it’s strength far longer than chipboard. Chipboard can often become a hazard. I’ve seen many a foot go straight through it after being rotted away from prolonged moisture.
The bounce! Chipboard can and often does bounce. Either over time or straight away depending on the thickness and quality. Although, in over 15 years I’ve seen very few that don’t bounce in one way or another. This leads me on nicely to my next point..
If installed correctly, plyboard doesn’t creek! If installed correctly chipboard often eventually does! With the explosion of fast, newly build homes over the past ten years and the increasing use of chipboard as a cheap sub-floor material, I’ve seen the common chipboard squeak too many times. If you have ever experienced it, believe me, you’re not alone! The squeak is basically wood particles rubbing together due to movement. As chipboard doesn’t have the core strength of plyboard, as mentioned, it can sag between joists. With this sagging comes bounce, with bounce comes movement, and with movement comes the squeak! Do not be fooled by people that say the squeak won’t happen if you glue the T & G with pva adhesive. This will not solve the eventual squeak..
I think you know by now my opinion. Although you may be enticed by the cheaper chipboard flooring, I have to strongly advice you not to be. Chipboard really doesn’t cut the mustard.
Is a saving of around £3.22 per square metre really worth the future under performance of a chipboard floor. After reading this, I hope you’ve come to the right answer and I hope you’ve made the right decision, choose plyboard. Although I sound extremely biased, I am so with good reason and good experience of both sub-floor materials.
Have you arrived here due to a failed chipboard floor? We now have a dedicated website dealing with squeaky floors nationwide. Call over and take a look at our example video’s to see what can be achieved…THE solution! www.squeakyfloorsolution.co.uk© Copyright 2013 Wes, All rights Reserved. Written For: Fitmywoodfloor