Laying A Pine Floor Home Improvement

Winter is winding down and I have started on some around-the-house projects that need to be finished so that I can sell this house. I have been (slowly) renovating for the past seven years and I’m finally near the end. Those who have followed along know about the roof and how I completed that last fall (September blog entry). There is only one major project left to do: the family room.
A structural support beam was installed in the ceiling of the family room to help shore up the second floor about three years ago and this required a drywall bulkhead built around it. The jack post that holds up one end of the beam needed to be boxed in as well and these two tasks are now complete. The ceiling has been repainted and now I can start work on the floor.

Late last summer I bought enough 6″ wide, tongue and groove red pine (also known as Norway pine) to do the floor. This has been acclimating ever since, and the moisture content of the wood has reached an equilibrium with the room – this should keep shrinkage to a minimum. Red pine is quite a lot harder than white pine, especially the slow growing northern Ontario variety that can hit a measured Janka hardness of ~1600 (this is interesting, as that would make it harder than hard maple) and this makes it well suited to flooring. To be honest, I don’t believe the stuff I have has that consistent hardness, as there are some pieces that seems to be a lot less dense and softer. The majority is fairy hard though and I think it will make for a handsome floor.

Here’s the material:

Laying A Pine Floor

The room has been used as a catch-all storage area and I’ve also used it as an assembly area over the winter for some of my projects, so it has accumulated some junk.

I have moved my big chop saw in to cut the boards to length:

Laying A Pine Floor

It’s set up on my folding saw horses. Most of the boards are 12 feet long and need to be cut to shorter lengths to make them more manageable. Over the winter, they have gone from about 16% moisture down to an average of 10-11%, and have become less than perfectly straight. To make them easier to lay, I’ll be cutting them shorter and cutting out some of the bigger or loose knots.

To make sure that each piece is of the same exposure (the overall width that the board covers, not including the tongue), I’ll rip some off of the groove side. The groove is deep enough that about an 1/8″ can be cut off and the tongue will still fit without bottoming out. To make these cuts, I have my utility table saw set up with an auxiliary fence attached to allow the tongue to fit under. With this, I can rip each piece to a uniform width:

Laying A Pine Floor
Laying A Pine Floor

To fasten the boards down, I’m just using a 16 gauge air nailer, driving the 2″ nails at a 45 degree angle through the tongue:

Since it will take several days to finish the floor, it wasn’t practical to rent a power nailer for flooring. I have the nail gun anyway and I also have the nails and this will do the job just as well.
I’m also gluing down every third row of boards with construction adhesive. This will limit expansion / contraction movement to the two rows between glued rows, and stop larger gaps from forming. It may be that the pine has dried to the point where shrinkage will not be an issue, but I think that this is a good idea anyway.

Here’s a look at one of the harder pieces:

Laying A Pine Floor

The grain is very tight, with the latewood (the hardest rings, grown in the later part of the season) nearly equaling the earlywood. This is a slowly grown tree and yields the best wood.

It takes time to get the boards cut, recut and laid, but I’m not in too much of a hurry. The room is large, nearly 600 square feet and there are many obstacles (doorways, etc.) to fit.:

Laying A Pine Floor
Laying A Pine Floor

I left some space at the walls for expansion, which is pretty much standard procedure for laying a solid wood floor. This gap is covered with baseboard after the floor is finished.
Also seen is the “blue stain” that this species is susceptible too. It’s a fungus that grows in the sapwood but has no effect on the strength of the wood. I have been selective and cut out the bigger sections of it, since it will show through the finish.

Close to half of the room covered and looking pretty good:

Laying A Pine Floor
Laying A Pine Floor

I’m butting the ends tight up against the brick of the fireplace, since there will be no baseboard or trim to cover the gap.

There’s a bit of a trick to cutting in the pieces around an opening like a doorway, and I go into detail in this video.

Laying A Pine Floor

To terminate the floor at the stairs to the basement, a piece is installed that becomes the top tread of the stairs. It’s solidly glued down with construction adhesive:

Laying A Pine Floor
Laying A Pine Floor

This needs to be square to the flooring as it is laid, and I used a framing square and level to extend the line to check this. It’s then nailed in place.

This top tread had the groove at the floor side and I cut the tongue in the ends of each piece as they were installed. I cut these on the table saw using the dado blade and a sacrificial fence:

Laying A Pine Floor

My brother Don helping out, he’s laying while I’m cutting:

Laying A Pine Floor
Laying A Pine Floor

The floor fully laid. I didn’t have much pine left over, probably enough to do the stairs up to the main floor and down to the basement and I’ll get to that after this floor is finished.

Transition to the ceramic tile in the washroom:

Laying A Pine Floor

The tile is lower than the pine, so the transition strip slopes down and lips over the tile.

The sander:

Laying A Pine Floor

It is an oscillating pad type, which is slower than a drum but safer, since it can’t dig in like a drum. I was also concerned about a drum gumming up prematurely, due to heat. This pine is fairly resinous – it hasn’t gummed up my random orbit sander when I’ve used that, but has gummed my belt sander and saw blades.

The sander uses 18″ x 12″ sanding sheets and I went through eight on the floor: two at 40 grit, two at 60, two at 80 and two at 100 grit. It took about an hour to make a complete pass on the floor for one sheet, so a little more than eight hours of sanding…a lot of sanding!

With the sanding done and cleaned up, I started the finish.
I’m using a mix of Minwax “American Chestnut” Polyshades and clear urethane to get this colour – about 1/2 litre Polyshades to 4 litres of clear. The colour I wanted is the colour that old pine boards go – not weathered, just darkened over time. It’s not overly dark and that is good for a floor like this this, since the wood is light coloured. If there are any scratches through the finish, they will be less noticeable.
It took quite a lot of experimentation to get this colour right and I tried several shades of stain on their own. The advantage of the stain / urethane mix is that it will give more even coverage, since it sits on the surface as well as soaking into the wood. The downside is that it needed to be carefully brushed on, leaving no start and stop marks and maintaining a wet edge. If you overcoat this when it’s partially dry, it will darken and that will be very noticeable.
The best strategy is to get the colour right in the first coat, then follow up with coats of clear after, to build protection. I would not recommend overcoating with the same mix after the first dries, as this will result is a streaky finish:

Laying A Pine Floor
Laying A Pine Floor

I let the first coat dry for 24 hours then put on the first coat of clear semigloss urethane. I didn’t sand before this first coat of clear – it’s not really needed and I didn’t want to run the risk of sanding through the colour into raw wood. I’m using a lambs wool floor applicator to apply the urethane and this really speeds things up. It takes exactly a gallon of finish to cover the floor in one coat.

After the first coat of clear has dried overnight, I lightly sanded with a 220 grit sanding block, cleaned the floor thoroughly and gave it a second coat. Here it is as it looks now:

Laying A Pine Floor

I will let this cure for about a week and then give it the third and final coat.
In the meantime, I can get started on the stairs and installing the baseboard and other details to finish out the room.