How to Install Douglas Fir Flooring over Concrete

How to Install Douglas Fir Flooring over Concrete

How to Install Douglas Fir Flooring over Concrete

August 2, 2011 by | Nicole | There have been 0 comments

We know that home restoration can yield lots of unexpected surprises. Like when you rip out the old linoleum in your historic home hoping to find Douglas fir floors. only to find concrete underneath. For many homeowners, concrete just doesn’t meet the wood floor standard. Douglas fir is everything concrete isn’t. It offers extreme durability while being soft on your feet. It’s aesthetically versatile – its tight vertical grain adds visible texture and depth in both natural and stained finishes. And, it lasts a lifetime with easy maintenance.

So, what can you do? Is it possible to have the Douglas fir floors you want without digging up the concrete you don’t? Yes, but, there are some things that you should consider before installing fir flooring over concrete. At Altrufir. we want to make sure you take the rights steps, so we’ve recruited John Mace. owner of Birdseye Hardwoods. to lend advice on what considerations need to be factored into your project.

Things to think about during preparation

Proper prep is essential in your concrete-to-wood project. Without it, you risk battling the effects of floorboards gone wrong. Cracking, splitting, warping, and money wasted are just some the headache…er, migraines, we don’t want you to have.

1. Check the existing concrete for irregularities. Use a level – the longer the better – to pinpoint any high and rough spots. John Mace, professional installer and owner at Birdseye Hardwood was quick to point this out, “Any gap or rise less than three-sixteenths of an inch is tolerable to wood floor installation; however, if the flatness tolerance is more than three-sixteenths in any one area, the concrete needs to be leveled.” This can be done by either sanding down the irregularities or using a self-leveling compound to fill in recesses. Compounds will only work on concrete free of grease, paint, oil, and dirt. In extreme cases, a fresh layer of concrete may need to be applied.

2. If the concrete floor is new, be sure it is completely dry before installing the hardwood flooring. We recommend waiting two months before placing wooden floors over new concrete.

3. Seal the concrete flooring using a moisture barrier. This prevents moisture from “escaping” from the concrete slab and running into your flooring. Allow the barrier to dry for 24 hours.

4. Ensure the room is at room temperature before the wood flooring is delivered.

5. Acclimate the wood floors to your home’s regular temperature and humidity levels. As with any type of wooden flooring installation, proper acclimatization is the key to long-lasting performance. We recommend leaving your Douglas fir floorboards in the same room for a minimum of 72 hours.

6. Consider whether your wood product needs a subfloor when installed over concrete. The team here at Altrufir does recommend using a subfloor for Douglas fir flooring because it reinforces the flooring and its performance over time. A ¼” thick plywood subfloor should be adhered to the concrete. Two ways to go about this are either direct glue installation or nailed down installation, which deserve to be featured in a post detailing steps to installation over concrete.

There are some wood flooring products that can be directly installed or “floated” over concrete, but other factors come into play such as moisture levels and climate type.

Things to think about during installation

When it comes down to the installation, there are a number of things to think about. John Mace over at Birdseye Hardwoods tells us his top three.

Wood speciesSome species are less likely to perform well when installed over concrete, like exotic woods. This usually happens because the lumber is not dried before shipment. Always check the manufacturer’s guidelines. I find that Brazilian Cherry is one of the more reliable exotics because of its resistance to moisture.

Douglas fir is very durable and its tight grain makes it a great choice for installation over concrete. Altrufir is happy to hear that, John. White Oak is also recommended. Again, check the manufacturer’s guidelines.

Board widthA narrower board is a little better. A three-inch board is the most stable width. Once you get beyond that, you have other forces acting on the board – temperature and moisture changes – that cause unpredictability in the wood’s performance over time.

LayoutThe overall layout can be tricky, especially if the customer is hoping to achieve uniformity by installing longer floor boards. The longer the board, the more susceptible it is to the effects of temperature and moisture changes, including cracking and splitting.

Altrufir offers you the best in clear vertical grain Douglas fir flooring. We stand by our product and want you to get the best from it. But, we also respect our experts’ advice when it comes to wood product choice. Here’s what John Mace had to say about engineered wood:

Engineered wood is a great product choice on concrete. Many people don’t understand how far engineered wood has come, equating it to laminate or even Pergo. It’s a sustainable product and a good solution to problem areas, especially over trickier concrete jobs.

Other considerations

We recommend installing wooden floors over concrete that is at ground level or above it. Anything below-ground is at risk of moisture and water damage. Case in point: water in the basement. If considering installing wood flooring below ground, John Mace again recommends checking with the wood manufacturer’s guidelines and making sure the concrete is moisture-sealed.

Expect a one to two inch height increase after installing the wood floor over a plywood subfloor over concrete. And, plan to make needed adjustments at doorways and with appliances in modified structures.

With all these considerations to, well, consider, plan ahead. Seeing as we’ve just scraped the surface on this topic, stay tuned for an upcoming post on specific steps to installing wood floors over concrete.

- Nicole Morales

John Mace, Owner, Birdseye Hardwoods LLC. 503-312-8085, www.birdseyehardwoods.com


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