Make Stuff by Hand Series: DIY Plywood Floor

CREDIT: Michael Huber Architects

You can use softwood plywood to create a finished floor surface. Depending on timber prices, this material can be less expensive than other products such as pre-made timber planks which are specifically made as flooring products. I used plywood in a bedroom and would do it again in other rooms. I wouldn’t install it in a hallway or anywhere with heavy traffic or heavy items being dropped as it will ding and dent.

CREDIT: Amanda Moore, installing hardboard insulation, working out the cutting list

I started with the subfloor of my 1950s house. You might have a concrete subfloor. I laid a hardboard layer, (the green material), which provides a little insulation, evens out any raised planks to make a flatter surface and is air permeable as I didn’t want to create any condensation issues around my existing subfloor. I removed the skirting boards as the new floor would be higher than the existing laminate which was there.

I bought standard 18mm plywood from my local DIY shop which comes in 2440mm x 1220mm standard size. I did a cutting list to try and fit all of the pieces I needed on as few sheets as possible. I wanted squares as the final finish with the grain running in alternate directions and so I divided the width of the room by 3 for the typical square dimension, allowing a few millimetres gap between each plank and 10mm against the wall all the way round.

The squares, when laid out onto a sheet of ply, left lots of odd offcuts and so I used CAD software to lay them out as a layer beneath the squares. The squares would be fixed to them to make a more rigid floor a total of 36mm thick.

CREDIT: Amanda Moore, floor installed and screw holes filled

The small pieces of plywood when cut easily stacked into my car. I countersunk holes in each corner of the top layer of squares and screwed them to the layer below. They were also fully glued and I applied wood glue with a big brush. So essentially, the ply floor is not fixed to the subfloor, it’s a big rigid floor made up of 2 layers of ply sitting on the hardboard layer.

The wood tended to have a nice side and then a not so nice side, (knot so nice side), which I laid to the bottom.

I then used a high-quality yacht varnish with a satin finish to lacquer the floor, after filling the holes  with wood filler in a light colour to match.

CREDIT: Amanda Moore, installing mineral wool and supports for cill

CREDIT: Amanda Moore, fitting the skirting and cill

​I bought high density fibreboard skirting which was pre-primed. The hardest part was cutting 45 degree mitre cuts for the corners. The adhesive was applied with a caulking gun and I pressed it against the wall with my feet!

There was a gap left against the sliding door. I added support battens and mineral insulation and then made a cill from Red Sapele timber.

I’ve built an oak parquet floor in another room which I’ll put in another blog post and the price comparison is very different. The oak ran me £40 per square metre plus glue and hardboard whereas the ply cost around £10 per square metre but per layer, so £20 per square metre and I got away with cheaper glue than the carpenter’s glue I needed for the oak. The whole thing was also done in a day.

It's a pretty simple way to make an attractive floor.