Random Thoughts on Refinishing Fir and Pine

As we’ve probably told you a million times already, Pete’s is proudly located in Minnesota.

So the lion’s share of our customers have floors made of northern woods like oak, maple, or birch. But the next most common wood in these parts is Douglas fir which we see on covered porches, in cabins, and on the second level of many 1950s baby boom houses.

We occasionally see a whole fir house, but they are usually c.1880-1900 and fairly rare.

Pine, which is botanically different from fir, grows extensively in Minnesota, but we do not see very many pine floors, except for subfloors.

But we do take a lot of consultation calls from the eastern and southern states asking about pine floors.

Long-leaf pine grows primarily in the southeastern states and is valued for its high percentage of heart wood. Long-leaf pine is often referred to as simply ‘heart pine’ and while it isn’t technically a hardwood, it behaves like one—its hardness on the Janka scale is just under red oak. The photo above is Pallmann Pall-X Power over a mixture of new and old heart pine.

We’ve taken several remarkable calls about heart pine floor in New Orleans post hurricane Katrina that survived the flooring and simply had to be refinished. Frankly, that makes us wish we had more heart pine floors in Minnesota.

Because fir and pine are so much softer than other flooring woods, sanding and finishing them is just a little bit different.

Here are a few of the things to consider:

When people discover fir floors in their newly purchased house, they often ask us if they should pull it out. Heck no! Even though fir and pine are considered “soft” woods because of their place on the Janka scale, they are not inferior to hardwoods.

Douglas fir is extremely strong structurally for its weight, and shrinks and swells less in response to changes in moisture than its hardwood cousins.

Almost all porches in Minnesota that date between 1900 and 1940 are fir because porches are unheated and fir shrinks and distorts less through the extremes of temperature and moisture of Minnesota seasons.

We also assume that it is popular for exterior porches in Minnesota because it is considered moderately rot resistant. Doug fir is somewhat prone to insect infestation, but our Minnesota winters take care of that.

The fir that was used on the second floor of 1940s and 50s housing was often considered a subfloor and you’ll see a lot of old square vinyl tile glued down over it.

This can be a heartbreaker because some of those mastics are so strong that the fir can split as you try to chip the tiles out.

The fir that was used on the second floor of 1940s and 50s housing was often considered a subfloor and you’ll often find it under a layer of those old square linoleum tiles.

This can be a heartbreaker because some of those mastics are so strong that the fir can split as you try to chip the tiles out.

If you have an historic fir floor that needs repair, you will need replacement stock.

This can be tricky for two reasons.

One, time really darkens fir, so putting in new fir boards to replace missing old fir boards can look shockingly bright. But finding reclaimed fir can be challenging.

It’s not salvaged as often as maple or oak. So usually the best approach is to “steal” some existing fir from a closet or other less visible location in the same property. You can replace the stolen area with new fir where, hopefully the color difference will matter less.

Two, the milling standard for fir was changed somewhere in the 1940s.

We haven’t found good historical documentation for exactly when or why, but we do know that pre-WW2 houses have fir that is 3¼” wide, but newly milled fir is 3 1/8”. It is a tiny difference, but it means you can’t just rip down new fir to fit.

Happily, there are some mills that produce both widths, but of course the old-style 3 1/8” width is more expensive. But Pete’s has a source for that narrower material and we do keep it in stock for in-store purchase so call or come on down!

Even though fir is a beautiful and serviceable flooring wood, it does acquire some blotching and mottling with age and use.

You can see from the photos that the raw sanded wood has what looks like grease stains, like when you put a potato chip on a piece of paper. You will not be able to sand or bleach these marks out. But we consider these the beauty marks of vintage fir and you should embrace it.

You will also find that firs and pines are more dentable and scratchable than oak or maple. This does NOT make it a bad floor. Never drag furniture across it (though this applies to all wood floors in our opinion), save your high heels for the dance floor, and don’t throw the ball for the dog inside and you should be fine.


Fir sands faster.

On the bright side, because fir is less dense than other flooring woods, it will sand easier and faster so we tend to be more conservative when we suggest a starting grit.

If you have an old fir floor with minimal finish left on it, 36-grit is often the perfect starting grit (by comparison, old maple almost always needs a 16 or 24-grit start, so be grateful).



What if my floors have been painted??

But if your fir is painted, as many porches and old bedrooms are, you will absolutely need 16-grit for the drum, and maybe even 12-grit for the edger. This is perfectly safe because the job of the mega-coarse grits it to damage the coating over your fir.

You’ll use these nuclear grits as first steps only- never try to sand to bare fir with a 12- or 16-grit; leave that for the later finer grits in the sanding sequence.

Many customer with older homes that are blessed with fir or pine floors still come to us with their Houzz wishbook pictures of stained brown floors, or nude white oak floors and insist that there is a way to get their fir to look like that.

This is always a difficult conversation. Fir is its own special self. Trying to stain it  brown or make it look like a different wood is a recipe for disappointment. The yellow and orange undertones of this wood can often turn browns into greens.

And the uneven, blotchy resinous nature of these woods makes it hard for them to take stain evenly, no matter the color. Bleaching them back to white is also a complex and unpredictable process.

So we strongly advise these customers to embrace their existing historic fir with all its quirks and beauties, rather than forcing it to be something it is not.

But, you can take advantage of some of natural coloration of fir and pine. When old fir is coated with a traditional oil-modified polyurethane or other oil-based varnish, it aggressively darkens the fir, almost as though it had been stained. But if you use a clear, waterborne urethane, the wood stays much brighter. Look at the photo of the door below. The frames, panels, and mullions were coated with a clear acrylic to keep it light, but the narrow mouldings around the panels were coated with an oil-based urethane. Look at the color difference! This can give you some control over the appearance of your pine or fir floor that doesn’t involve the unpredictability of pigmented stains or finishes.


Do you need advice for your specific hardwood floor problem?

Get a one-on-one phone consultation with a hardwood flooring expert. For a small fee of $25, we can provide the wisdom and knowledge that you need to complete your hardwood flooring project. When you don’t know what you need to do next, that’s when it’s time to call Pete’s Hardwood Floors Help Hotline.

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Here are more common floor issues.