Hardwood Flooring Layout - Which Direction. Diagonal?
Choosing which direction to install wood floors is 
often a confusing choice for many. In a nutshell, the preference calls for running the flooring front to back as you enter the home. By way of explanation, as you walk into the foyer, the floor will be installed perpendicular to the front door threshold.
The example shown is our Country Style random width Walnut. If the front entrance is rarely used and the main focal point becomes another point of entry it may be better to go perpendicular from there.
Floor Joist Direction Can Mess It All Up
More modern homes have a floor joist system and a subfloor. Experts have always been aware of the effect floor joist direction can have on the performance of solid 3/4 inch hardwood floors. The preference has always been installing perpendicular to the joists, as it provides stronger support for the floor going over it. Installing with the floor joist system or parallel, can lead to sagging or board separation.
Other Random Plank Examples
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| Country Lifestyle Night Rider Hickory Random - 4 ¼, 6 ¼ & 8 ¼" |
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| Country Lifestyle Gentle Breeze Hickory Random - 3 ¼, 5 ¼ & 7 ¼" |
The Solution To Fix The Mess Up
For years most construction has been using common 5/8 or 3/4" sub flooring over joist systems. In some cases thinner material may have been used. None of these are suitable for a problem free floor installation running parallel to the joists. Sure in some cases it may work, but others not. Why take chances considering the price of wood floors today?
Fixing the underlying problem is as simple as adding another layer of plywood to the existing subfloor, providing your floor joist spacing is in a normal range. Many suggest 3/8" plywood to be used if you prefer running with the joists. When installing, run the new subfloor material perpendicular to the existing while overlapping older subfloor sheets(seams). Applications ordinarily call for gluing with a construction adhesive, while screwing or using ring shank nails secured into the floor joists through the
existing subfloor.
Older Plank Sub Flooring
Older homes with thicker solid plank flooring were installed on a diagonal. Any new hardwood installation does not require additional sub flooring unless the preferred direction is the same as the old plank subfloor. Other situations where attention should be taken into account would be if thinner sub flooring was used, or settling of the home had taken place with visible peaks and valleys across the subfloor.
Concrete
Hardwood on concrete does not follow any of the above. There are no structural subfloor components that can effect the performance of the hardwood floor except prestressed or precast concrete. These type of subfloors have been constructed off site. Consult with experienced professionals to evaluate these systems and what may or may not be needed in your case.
Other Considerations
Experienced installers have a better grasp on which direction the floor should run. A little off subject, but if you have a lightweight concrete subfloor often called gypcrete, some hardwood floors can only be installed by the floating method. Direction can also play a role by opening up areas that looked smaller.
Straight Laid Or Diagonal Floor?
Diagonal floor installations can be installed on both plywood (minimum sub floor requirements) and 
concrete subfloors. Diagonal installations are not very common because few salespeople bring up the suggestion, or the contractor doesn't want to handle it as the time involved increases.
In my own personal opinion, diagonal installations at a 45º angle will make your home stand out in the neighborhood. It's not uncommon after finishing up a job, neighbors come by to casually snoop and ask themselves.."why didn't we do that?" Expect higher installation rates and material waste when installing on a diagonal.
How To Install Hardwood on A Diagonal
Opinions on how to install a diagonal hardwood floor may vary depending on who you talk to. First off, what is a diagonal? For the most part, diagonal installations show the floor layout on a 45 degree angle, but that does not mean you’re held to those dimensions only. A few variations can really set off the appearance of your home. Take for example the installation shown further down the page. Instead of a standard 45 degree layout, or the bowling alley look, this homeowner sought a ten degree layout.
Where To Start?
I’ve found the best area to start is in a corner. The image below best illustrates this. Keep in mind our example is a glue down installation and the procedure may vary. Principally what I wanted to achieve was a good solid starting point. The smaller sections behind the first board are anchor points to keep the first board aligned.
Other applications can include using a full length piece as a backer board for the start of the installation. Either method, they are held firm to the subfloor with concrete screws. No movement of the starter line area will occur, but keeping a watchful eye on the area is advised during the course of the first several rows.
For the starting area there is no set method on how far out from the corner, but you may want to dry lay pieces in the area if you're not fond of small triangles in the corner. In this example I simply took a three to four foot board, cut two outside 45 degree angles on the miter saw, placed it into the area finding a comfortable starting point where enough expansion space area was allowed.
The job below was used with our 3/4" unfinished engineered floors.
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Starting area in corner |
Inserting wedges |
Thoughts To Consider
Diagonal installations have a tendency to bend at the perimeter because there is not enough backing to keep it aligned with the firmer larger areas. Bending can be slight, but over many rows can throw off the alignment into inches if you don't keep an eye on it. This is where wedges come into play. After every row or two is completed, insert the wedges against the wall or base. At all times keep an eye on your control line. More on control lines can be seen with our naildown pages as a reference.
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Wedges against baseboard |
Finishing floor |
The Ten Degree Layout
The ten degree angle layout is not for the timid. Patience is critical with this type of installation especially in keeping the proper amount of expansion space around the perimeter. Generally the biggest problem is keeping the same angled cut around the
wall lines with so many individual pieces being used. Standard chop saws cannot cut past 45 to 48 degrees without using a jig.
For those interested, the easiest way to make these cuts is establishing a template with a two foot long scrap piece. Once the preferred angle is achieved simply create the template board to be used throughout the installation. As far as tools used to cut, any table saw will be the most efficient, but not the safest. Proceed with the utmost caution as blade binding with severe angles is commonplace. This often results in board kickback from the saw itself. A much safer tool to use is a jig saw but takes longer.
The easiest way to install a ten degree angle (80 degrees at the other end) is to begin the flooring along the walls that represent the 80 degree angle. This way your final cut along the opposite wall will be easier to measure and cut.
Directional Changes
Some ask.."I have this long hallway. If I install the flooring front to back of the entry, it will look all chopped up in the hallway. What can I do?" It's not uncommon to have directional changes that offset the appearance, providing you have the proper sub floor. The examples shown on this page are part of a directional change done for a showroom.
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Directional change |
Showroom |
Image Source: Bill Price (10 degree layout)
Measuring
Proper Subfloors
Moisture Testing Awareness & Control
