I have a large installation, 4500sqft. on two floors and am trying to figure out how to best handle the layout. My problem lies in the amount of expansion across a 54ft run. The main floor lay is in an H pattern from a grand hall through a hallway and then into a large dinning area. The run for each room is 17ft, 20ft then 17ft. Other rooms also join off of this main central hallway. I have double doors at both entrances to the hall way. What I would like to have is a boarder in the three main rooms continuing through the double doors. However, I am concerned that the distance will cause too much expansion and contraction thus separating the 45deg boarder joinery.

I live in New Brunswick Canada which has a large humidity fluctuation from the winter to summer months. Trying to keep the humidity between 40-50% to keep the wood stable conflicts with my new wood frame window manufacture which recommends the following

Exterior temperature Max. interior humidity level
-22°F (-30°C) or less 15%
-22°F to -11°F (-30°C to -24°C) 20%
0°F to 10°F (-18°C to -12°C) 30%
10°F to 21°F (-12°C to -6°C) 35%
21°F to 32°F (-6°C to 0°C) 40%



So what to do with a 54ft. run? What lay direction? I can only think that having a border may cause to much aggravation. My other preferences include not having a “T” molding between the three main rooms at the double doors. Is that recommended or possible?

The only way I can figure to accommodate the hallway expansion is to include a slight crack at every board within the hallway field and laying the outside room floors away from the hallway.

Any suggestions would help.

4500? Is it a castle?
A 54 foot run for expansion, speicies will paly a big factor as well as board width

Yep it’s big. And I need big time advice.

I'm using 90% edge grain Douglas fir with 5 1/4" width.

With this plank style I'm guessing you would suggest using a glue and nail installation? However, I was kind of thinking on using the felt and nail only. My reasoning is, although the basement appears dry, the house is built on a historic foundation and hence a felt underlay is preferred

I would definatley glue it, no one is going to back anything on your floor if you dont, it may sqeak/pop ect from day one if not glued. (4500) ft is a BIG investment, hate to see it wasted. If needed because of the historicness lay a substrate 1/4 plywood 3/8ths and screw it to death (or staple) then glue to that.

Dont work with fir, so dont really know its charetoristics(sp?) So I am actually not much help on the expansion issue

Thank you for the post on fastening. You are probably right. But this leads to another question. Will a glue and nail installation still allow for expansion?

I should mention my underlay is 3/4" t&g ply on top of engineered trusses spaced 16".

I use bosticks best, its some special formula designed with elasticty to the glue to allow for expansion. I cant say why/how it works (Im no scientist, but it does work)

Going with that width, you could nail it only but expect some more movement than nailing and gluing. I have worked with Doug Fir a lot. Typically, it is a 3.25" or 3.5" width, which would be better for a nail down only floor. Plus, I'll bet your flooring will NOT be end-matched (T&G) on the butts. Fir typically is not. And another reason for gluing. Fir flooring has traditionally been utilized as a utility type floor. And is normally oiled or painted. But I've refinished and installed many and we would usually just apply straight polyurethane. I am confused by the window manufacturer's guidelines. They recommend 20% humidity? That's very low and everything in your house is going to shrink. All framing lumber is green, unless you specify KD. And even then, it's not real dry. If you want creaks, gaps, noises, popping sounds and cracks, keep your house at 20% RH. Otherwise, 45% is the correct RH for most homes in North America. You will need a humidistat during winter months and maybe AC in summer. And fir flooring, if properly milled, acclimated and installed, is somewhat more stable than oak, meaning less seasonal movement. Having straight grain helps as well. If it were me, personally, I'd forget the border thing with a 5+" plank. It just doesn't look right. Strip flooring is for borders. Plank is for straight lay. If you want a feature strip in a room, you could have an artist paint one on before the final two coats of floor finish. Commonly done with lessor grade floors. Just lay the flooring perpendicular to the joists. As I said, you can "get away" with nailing only. You just may have a little more movement (up and down + side to side ). A lot of fir has sloppy T&G's and isn't a snug fit. Another reason for adding glue to the install method. In the end, it depends on the "quality" of install you want. I did 4500 of Carlisle Wide Plank Pine a few years back. We nailed it and glued it with PL400 (the old stuff; not the new VOC crap) per Carlisle's instructions. It was fine. It took me and another guy 3.5 weeks to install it, working about 7 hrs. a day.

Thanks Gary for the response.

I never considered dougfir as a utility grade? I would more expect any wood could be used as utility if the quality was substandard. To label an individual species as such is a little harsh I think?

I’ll take your advice on the boarder but I still wish for some feed back on layout. Particularly how I can accommodate a 54ft run. Is there a way to account for expansion at doorways without using a T molding? And what about direction of lay? From the centre out ward?

My plank flooring will have end matching and from what I can tell the tolerances are pretty tight. The cost of it sure is not utilitarian.

My bit about the window manufacture is to show my confusion. As it appears flooring gurus recommend consistent humidity and other manufactures want seasonal fluctuation. What is a home owner to do? When some of us live in the northern climates it appears trying to keep the humidity constant may be impractical due to the outside temperature differential. I can only guess I’ll try to minimize the difference.

My next question- Do any of you paint the bottom side of your flooring (before it’s laid down of course) to have a two sided covering? I understand this should help in minimizing MC absorption.

If you read my first reply, you see I used the term "traditionally". This means "in the past". Here in the Pacific West Coast, where fir grows and has been most used, fir flooring was mostly used as a utility floor in stores, factories, truck beds and as lessor expensive flooring for secondary rooms of residences. Today, clear, straight grain dog fir costs nearly the same as oak in the same grade. But this wasn't always the case. Most quality Oak comes from the East Coast of the USA, with the south being the most productive. This made using oak and other hardwoods costlier on the west coast. So, traditionally (in the past), pine, cedar and fir (native to the west coast) were used in place of hardwoods where cost was a factor. I have seen many examples of this in older homes around the SF Bay area and on the west coast of the USA. In the formal rooms such as the Entry, Dining room, Parlor, etc. "expensive" hardwoods were used, such as oak. And at the turn of the 20th century, oak was the primary hardwood used on floors, with maple being a close second. But in other areas of the home, like bedrooms, mud rooms, servants quarters, etc. fir flooring was commonly used. In fact, 3.5" doug fir was commonly used as subflooring. Even for interior trim, fir was considered a "cheap" alternative, with hardwoods being preferred. In Arts and Crafts styled homes, clear Redwood was preferred over doug fir. But today, things are different. Japanese builders prize doug fir for it's strength, clear grain and color. And utilize it a lot. They import lot's of doug fir from Canada and the USA. And doug fir is king when it comes to structural framing wood and glu-lams. For flooring, fir is generally considered less than ideal due to two reasons. It dents way easier than oak. And it doesn't stain as easily as other american hardwoods, like oak, ash, cherry and walnut. But for those who want the look that only doug fir can provide. And are willing to accept it's tendency to dent easier, then fir is an ideal wood for flooring. However, the reality is, doug fir, historically, has always been considered to be a less expensive wood floor alternative to oak and a utility grade floor.

Ok Gary, I can understand what your getting at and your response is vary informative. Thank you for clarifying.

I still however, need some advice in layout with this long run. Can you give me some input on a total run of 54 ft. going through three rooms? Refer to my first post.

What I’m most concerned about is the hallway in the middle that separates the two main rooms. For the lay pattern to cross the joists would result in parallel lay throughout the three rooms, which I like. However, this then causes for no expansion space in the middle hallway with a 20ft run. Hence my problems of having a 54ft total run traveling into the outside rooms.

I wish not to have T moldings at the 5.5ft wide entrances to the hallway because of the visual effect from one end to the other. The three rooms are a main traffic flow.

Go Fd go

I've never seen Fir in person and wonder what the texture and color is. Someone wrote on here how incredibly soft Fir is. I think it ranks less than 700 on the Janka hardness scale and is not good for much abuse.

I am assuming this is not a pre-finished floor. Except you keep wondering about a t-moulding. I have never used or seen a t-moulding used with a site finished floor.

You described a H style layout...a picture (or diagram) is worth a thousand words. I am surmising that you may have the grand hall as one side of the H, then the hallway joining the large dining area as the other side of the H.

If I am correct. I would also guess that the hall is 10' or less in the width. Regardless of any other facts (joists or subfloor or other rooms) I would desire to lay this hallway with the boards running the length of the hall. Perhaps in the grand hall and the dining area the layout would be laid perpendicular to the hallway. This should be considered. Also wood will expand across the width not the length so much. So your concerns for expansion can be dealt with by perhaps changing the layout from room to room.

I am not so geeked up on this computer stuff as to be able to post pictures, PDF, or diagrams , but I know folks do it.

Barquios your assumption is correct on the floor plan. The joists do run the length of the hallway with more rooms and a stair well on either side. I have also thought of using blocking in this section but there is HVAC ducking running between the joists.

The flooring will be site finished.

The T molding was something I was going to custom make. It is the only thing, I figured, that would help solve the problem. Other than laying at a 45deg I can’t think of any other way to combat my problem.

With respect to Fir characteristics, yes it is on the softer end of the Janka scale. It does though range on this scale depending on where it grew, tightness of grain, and how much edge grain versus flat sawn. Generally coastal wood grown on a dry site is the hardest of the Firs. The colour is a salmon shade which darkens with time. The texture has pronounced parallel grain pattern in quarter sawn and plywood like with flat sawn.

Here is how I would solve this problem. I would lay the hallway along the length. Thus, expansion in the hall will be toward the side walls, not down the length. Also this is more pleasing to the eye, having the boards run the length. The fact that the joists run with the length of the hall as well, is not that big of a consideration for me. It will be hard to stand at one side of the hall and look across to the other side and see any waviness to the floor due to inadequate support. Though, if you were concerned adding additional sheeting to the floor to beef it up would allay your fears.

Then each of the other rooms would be laid beginning at the hall working toward the exterior walls. When wood expands due to moisture it expands more toward the tongue than toward the groove, and not down the length of a board either.

Thus in these rooms the expansion will be away from the hall toward the exterior walls. If you then make sure to either under cut your drywall, you could use that as additional room for expansion, and not need to use such a heavy baseboard to cover it up. At the exterior doors you could create a transition than would look appropriate and still allow for expansion