Should I consider washer rows in my 1-1 - 2” x 3 - 4” T&G red oak hardwood flooring layout?
I’ve just finished laying out roughly 120 sf of 1-1/2” x 3/4” T&G red oak strip flooring and before I begin nailing it down, I wanted to pause to determine whether I should consider washer rows based on the following knowns:.
House location: Austin, TX.
Relative humidity in house (has central a/c): 60%, which I understand to be a bit high but I think is close to average for this 1940s (w/1980s addition) house based on past measurements.
Flooring package: pier and beam with beam spans of 4’, 2x6 joists 24 o.c., 1x6 pine subfloor on the diagonal, new 19/32” Exposure 1 plywood underlayment, Aquabar “B” vapor retarder.
Crawlspace under house is well-vented (per flood zone requirements), but there is no insulation, vapor barrier, or plastic sheeting over the ground.
Length of time of the flooring has been stored in this house: approximately 1 year.
Current MC of the flooring: 6% (consistent across all bundles from a lot of 250 sf).
Length of time the plywood underlayment has been in place: approximately 6 months.
Current MC of of the plywood underlayment: 9% - 10%.
Room size: 12' x 10'.
Layout: center, outward from roughly the center of the room; boards running perpendicular to the longest, 12', wall (eventually carrying through to the adjacent hallway that was used as the "longest wall" reference point).
Planned perimeter gap: 3/4”.
In the original rooms of the house, there is also 1-1/2” x 3/4” red oak installed directly over the 1x6 subfloor—so no plywood underlayment and no vapor retarder that I’m aware of. The MC readings of this flooring varies from 9% to 11%, with some adjacent boards varying by 1%. Aside from all the physical wear, the floor is in good condition: no buckling or significant gaps throughout.
The hardwood flooring that I just laid out was been stored in an adjacent room in the same exact spot for the past year and has MC readings of 6% across all sample boards, including those in the center of the stack and those directly in contact with the room's plywood underlayment (room is currently functioning as a shop for this house remodel, the flooring taken down to the plywood underlayment).
On another message board I asked the same question and one responder recommended using a few washer rows over the course of the room's layout. Would any of you experts out there recommend the same approach?
Many thanks in advance for your valuable thoughts!.
Question from user Chris at stackexchange.
Answer:
I had to look up "washer rows", never heard of the term. Now I have. If you start in the middle of the floor and go both ways, you are working to the advantage of any expansion that may occur. The staples or nails are oriented in such a way that will allow the flooring to expand in both directions.
All your MC readings are great, I think the expansion room at the edge are excessive, 1/2" would do so 3/4" base will cover without shoe mold.
In my experience, it takes about 2 weeks of a controlled environment to get material down to where it will stabilize. One note, sometimes when checking the MC of hardwoods and softwoods with the same settings on the moisture meter (MM) there is a correction table used to get the actual reading of MC. You may be closer than you think.
Another consideration is the cut of the flooring. AS in plain sliced or flat sawn, rift cut or quartersawn. All this affects how the wood reacts to moisture, quarter sawn being the least reactive, rift sawn slightly more reactive and flat sawn, the most.
In my personal opinion, you do not need a washer row. In my brief looking up what it meant, washer rows are only used on large jobs, I'm thinking 1,000's of feet, not hundreds of square feet.
Answer from user Jack at stackexchange.
I’ve just finished laying out roughly 120 sf of 1-1/2” x 3/4” T&G red oak strip flooring and before I begin nailing it down, I wanted to pause to determine whether I should consider washer rows based on the following knowns:.
House location: Austin, TX.
Relative humidity in house (has central a/c): 60%, which I understand to be a bit high but I think is close to average for this 1940s (w/1980s addition) house based on past measurements.
Flooring package: pier and beam with beam spans of 4’, 2x6 joists 24 o.c., 1x6 pine subfloor on the diagonal, new 19/32” Exposure 1 plywood underlayment, Aquabar “B” vapor retarder.
Crawlspace under house is well-vented (per flood zone requirements), but there is no insulation, vapor barrier, or plastic sheeting over the ground.
Length of time of the flooring has been stored in this house: approximately 1 year.
Current MC of the flooring: 6% (consistent across all bundles from a lot of 250 sf).
Length of time the plywood underlayment has been in place: approximately 6 months.
Current MC of of the plywood underlayment: 9% - 10%.
Room size: 12' x 10'.
Layout: center, outward from roughly the center of the room; boards running perpendicular to the longest, 12', wall (eventually carrying through to the adjacent hallway that was used as the "longest wall" reference point).
Planned perimeter gap: 3/4”.
In the original rooms of the house, there is also 1-1/2” x 3/4” red oak installed directly over the 1x6 subfloor—so no plywood underlayment and no vapor retarder that I’m aware of. The MC readings of this flooring varies from 9% to 11%, with some adjacent boards varying by 1%. Aside from all the physical wear, the floor is in good condition: no buckling or significant gaps throughout.
The hardwood flooring that I just laid out was been stored in an adjacent room in the same exact spot for the past year and has MC readings of 6% across all sample boards, including those in the center of the stack and those directly in contact with the room's plywood underlayment (room is currently functioning as a shop for this house remodel, the flooring taken down to the plywood underlayment).
On another message board I asked the same question and one responder recommended using a few washer rows over the course of the room's layout. Would any of you experts out there recommend the same approach?
Many thanks in advance for your valuable thoughts!.
Question from user Chris at stackexchange.
Answer:
I had to look up "washer rows", never heard of the term. Now I have. If you start in the middle of the floor and go both ways, you are working to the advantage of any expansion that may occur. The staples or nails are oriented in such a way that will allow the flooring to expand in both directions.
All your MC readings are great, I think the expansion room at the edge are excessive, 1/2" would do so 3/4" base will cover without shoe mold.
In my experience, it takes about 2 weeks of a controlled environment to get material down to where it will stabilize. One note, sometimes when checking the MC of hardwoods and softwoods with the same settings on the moisture meter (MM) there is a correction table used to get the actual reading of MC. You may be closer than you think.
Another consideration is the cut of the flooring. AS in plain sliced or flat sawn, rift cut or quartersawn. All this affects how the wood reacts to moisture, quarter sawn being the least reactive, rift sawn slightly more reactive and flat sawn, the most.
In my personal opinion, you do not need a washer row. In my brief looking up what it meant, washer rows are only used on large jobs, I'm thinking 1,000's of feet, not hundreds of square feet.
Answer from user Jack at stackexchange.