The subfloor should be contructed of 5/8 inch or thicker plywood, when installed over 16 inch center joists. My subfloor was 3/4 inch on 16 inch centered joists
Bellawood states the following;
The relative humidity level in your home must be maintained at 45% (40-50%) throughout the year. Hardwood flooring reacts to changes of relative humidity. It absorbs or releases humidity with the seasons. Consequently, its dimension changes.
In the summer, when humidity is at its highest, it is absorbed by the wood which then expands. The expansion causes the strips of wood to push against one another. This could result in "cupping". These variations can be minimized with proper ventilation, dehumidifying or heating.
In the winter, when the heating system is on, the relative humidity level in the house is much lower. The wood releases its humidity and contracts or shrinks. It is recommended to use a humidifier in order to minimize shrinkage effects.
For new construction or remodeling, the heating system must be operational, and the house must have been heated for a week at 71 degrees F. Plastering and concrete work must be completely dry (45 to 90 days old). Check basements and underfloor crawl space to be sure they are dry and well ventilated, in order to avoid damage caused by moisture. Flooring should be left to acclimate at house temperature for a period of at least 24 hours at the recommended relative humidity level.
Using a moisture meter, available from Bellawood , check the plywood (subfloor) moisture content. Moisture content should not exceed 12%. If the moisture content is too high, delay the installation and turn up the heating system, increase ventillation, or open the basement windows slightly.
Temperatures were 90F and above with Relative Humidity as low as 8%, with no central air or humidifiers I decided to deviate from the instructions. The house conditions were steady for months with inside temperatures in the high 70's, the hardwood flooring was left to acclimate for 2 weeks. I took no moisture readings, this place is a desert.
I removed the baseboards but not the door sills (as Bellawood instructions state) and then I removed the old carpet, carpet pad, and tac strip were removed. Inspection of the subfloor revealed little defect and was lightly scraped to identify raised nails and other anomalies. Nails were hammered down and old paint and stuck on debris was removed. A 4ft level was laid on the floor and using a sweeping / rotating motion the floor was checked for level to reveal that the floor was level within an 1/8 of an inch at most. Using a "jamb" or "undercut" saw, the door frames were cut 3/4 inch above the subfloor to allow the hardwood floor to slide underneath. The room was now swept and vacuumed.
Next Bellawood recommends creating a sketch of the installation, I have installed a laminate flooring before so I did not feel the need to sketch. Bellawood recommends that the planks are laid parallel to the longest length wall of the room to avoid the 'ladder effect'. This room is approximately 12x13 and contains a 3ft x 3ft (approx) entryway. It is also recommended that the flooring is installed perpendicular to the floor joists to increase the stability of the flooring (joists, subfloor, hardwood floor). I decided to lay the plans perpendicular to the floor joists although this created the ladder effect in the entryway to the room.
Bellawood recommends installing a #15 felt floor liner or construction paper and this is where my creativity continues. I decided to use trafficmaster 3 in 1 underlayment for both laminate and hardwood floors. This underlayment provides sound, temp, and moisture insulation. The underlayment itself had instructions which I did not follow, time was short and the instructions said something about unrolling the underlayment and letting it sit for 40-70 hours or something. Instead the underlayment was unrolled and the planks were immediately laid.
Using a chalk line, draw a guide line parallel at 3-inch (7.5 cm) of the starting wall for the strips of 2 1/4-inch (5.7cm) wide, or 4-inch (10cm) for strips of 3 1/4-inch (8.2cm) wide, considering the 1/2 inch (1.3 cm) minimum expansion space between the wall and the first strip, and another 1/4 inch (6mm) for the tongue. This guide line must be at a 90 degree angle to the adjacent wall. It is very important to start straight and square.
Spacing was considered but I didn't draw a chalk line nor did I measure, why? Lets see the end result before you ask.
Next I selected the strips to lay for the first row, the planks must be inspected prior to installation to ensure quality. Some planks do have manufacturing defects with finish or milling and some planks do get damaged in shipping. All in all, defects and damage are minimal, maybe 3 planks per box should be put aside, these pieces shouldn't go to waste though, they can be cut and used at the end of a row. The first row can not be nailed with the floor nailer due to the clearance the nailer requires so instead of using finishing nails I used 3 and 1/2 inch deck mate premium all purpose exterior screws. Laying planks down with the groove edge towards the wall, screws were counter sank at least every 8 inches with screws securing the planks into every joist, depending on the size of the plank screw spacing could be closer. At the end of the row, a 1/4 inch gap is left between the last plank and the wall (expansion), ensuring that the last plank on every row is at least 10 inches long and the last plank is secured at most 3 inches from the wall.
The second row of planks has the clearance for the floor nailer and this is where the fun begins. Stagger the planks so that planks break as far as possible from where previous row's planks break. Make sense? When using the manual floor nailer DONT BE SCARED, you have to hit it and hit it hard, let the 5lb mallet do the work for you. Still as hard as you try you will find scenarios where the nailer isn't hit hard enough. This occurred for me quite often when the wall was on my right (facing the unfinished part of the floor). When the cleat isn't driven all the way you have two options, continue to drive the cleat with a hammer and / or punch or you can remove the cleat, drill a hole and drive a cleat (by hand) into the hole. If the cleat is left extending too far out of the plank it can be tricky to drive it in by hand, one wrong move and the cleat will bend. Drilling a hole half the size of the cleat and then driving a cleat by hand works well. If the cleat protrudes 1/4 to 1/2 inch it will be easy to drive it in with a punch. Every cleat you drive with the floor nailer should be inspected to ensure it is at least flush, otherwise the cleat will push against the groove in the plank in the next row, creating a gap.
Bellawood recommends laying out the next 6 to 8 rows to ensure proper use of remaining planks. I didn't do this as I kept an eye on the stock I had to pull from ensuring a fairly equal amount of short and long planks remained throughout the installation. Next room I do I will follow this instruction as I see it more efficient to select planks, lay the floor and install it, rather than more frequent alternating between selecting, laying and installing, back and forth, back and forth ...
As you approach the end, the flooring nailer clearance issue presents itself for the last 4 to 5 rows. This is where I drilled a hole in the tongue so that I could manually drive cleats, until the last row where there was no clearance to drill or manually drive a cleat. For the last row I counter sunk the screws as I did on the first row.
Here are a few additional tips from Bellawood;
to make your job easier, should you decide to use a manual hardwood floor nailer:
1. Prevent any scratches and indentations of the surface of the board by keeping the nailer plate (base) clean, free from nicks and scratches at all times, and also by putting down the nailer on the plywood or on a piece of cardboard, not directly on the prefinished floor.
2. By adopting a standing position while using the manual nailer, you will deploy more strength when you drive the nails in. Nails that are nearly embedded can be driven in place by using the hammer and a nail punch.
3. Hold the nailer firmly in place and hit the head of the nailer with the rubber end of the mallet.
4. Make sure the nailer base is squared and sits well on the edge of the strip to avoid damaging the edges of the strips.
5. Verify regularly the hardwood floor nailer is in working condition to prevent damages to strips.
So what about that chalk line I never ran, and the spacing that wasn't measured? At the other end of the room where the hardwood floor meets the wall, one word; DEAD ON EVEN.
So far I am quite happy with the installation of this hardwood floor, if I had it to do over again (which I will with the next room) I might pay more attention and therefor be more selective with choosing planks. All in all though there are probably 3 or 4 planks in the whole room, if I could I might choose different pieces. Time will tell how my disregard for the directions plays out, but so far so good.
Lighting conditions in the room are less than favorable for photography so here are a couple to choose from;
This post leaves quite a bit to the imagination such as working around doorways and installing transitions. Once I can get my thoughts together on describing working around doorways, and once I install the transitions I will post that information as well.
Here are some pics showing how the rustic maple works with other grains and colors of wood;