Hello. I'm about to do installation work on some 5" hickory solid pre-finished wood at my home in NH. My first assumption was that I'd be doing a standard installation on this. At this point I am not so sure...


One local installer I talked to said that they will do glue and nail on any of the 5" boards. A contractor who does work for me says definitely not to use glue as it could split the wood over time. The flooring supplier said it should not likely be needed, but wasn't direct on what needed to be done. Since then I've been doing some poking around and I've seen all sorts responses. I'm looking for more input on what I should do.

All of the install is on top of plywood. We live in NH. The heating is forced hot air (not sure if we have the system to add humidity, if so it has never been used) and we have central air in the summer, which does not get run all the time. Most of the area had carpet previously. One section has wood now which I will be pulling up to do this.

There will be two separate hallways done. One of the hallways extends into the master bed at the end (total length end to end could be 47'). There are two smaller bedrooms which attach to the hall.

I'm looking at a 5" hickory solid 3/4" board.

When looking at the installation instructions for some larger manufacturers it seems to indicate above 4" the glue "can" be considered.

The NWFA installation guidelines gives adhesive as a suggested option at 5" or wider.

I've seen a number of sites which caution against using glue because the wood needs to expand / contract. Other posts indicate anything over 3" wide people always glue. There seems to be a wide variation in what is done.


Relative to concerns over damage...is flooring adhesive made to allow for expansion in the lateral directions?

If I do go with an adhesive it seems I can do one of three things based on what I've seen.
1. Use caulking gun to apply to back of each board and apply without a vapor barrier. I assume the glue is somehow the barrier.
2. Spread out with a trowel, and use this as the barrier.
3. I found one place recommended applying the barrier and between each strip of the barrier leave a 1" gap where a single strip of glue would be applied, perpendicular to the direction of the planks.

Based on the final installation method, can anyone recommend some products?

Thanks

Its there for a reason, just do it - plus Hickory likes to move more than other woods. Following directions is better than wishing you did it afterwards when the floor is failing.

To do the glue method without any vapor retarder you first need to take extra precautions the crawl space or basement is sealed up tight and dry.
Which you should really do anyways.

If you full trowel your going to have to trowel one row at a time otherwise your nailer is gonna get messy. Some people do squiggly lines, some do perpendicular to length lines every few inches or so. Never heard of the combo retarder and lines.

Thank you for the reply floormeintucson. I don't mind doing the adhesive, although in the back of my mind I'm concerned that locking it down will make the wood split when it wants to move. But it seems that the majority of people lean toward the adhesive.

My basement is pretty dry and I run a dehumidifier to keep it around 45-50% RH.

Is there any sort of vapor retarder which which can be used in conjunction with the adhesive on the back side of the plank? It seems like it could be risky not having any protection there.

Do you do the trowel yourself?

A little off topic but I am doing a 5" floor as well, and I was curious as to why you are choosing to go with Hickory.

We have kids and dogs and cats... we were all about the hardness rating. I know any floor can still scratch, but we want it to wear as best as we can. Cosmetically we like the grain as well.

I guess the down side is that it is going to move more than maybe an oak.

Why not an engineered Hickory? Or is it too late? My engineered aren't priced for everyone but you get more benefits that a solid cannot offer and you don't have to go through the additional glue procedure. However, as Stephen mentions, it's wise to have as many bases covered regardless of what you use for a problem free floor for life.


Prefinished & Unfinished Hickory Engineered

I double checked today and the subfloor is 3/4 OSB rather than plywood. Does that change anything in terms of install?

I'm about to install 4" hickory as well. The manufacturer of my floor (Mullican) says this:



When I first read this I thought they wanted adhesive on the fastener too but realize they mean adhesive on subfloor and also nailing flooring down.

Matt

I will strongly recommend glue down full spreads use only proper glue for flooring do not use construction glue.

Hickory is very unstable wood will move, the glue like Bona , Bostik or similar will do the job there are design to move with the floor, full spreads do not required nails ,on top if you nail the floor specially engineered most manufacturer will not cover squeaks under warranty

Any solid wood over 3" i will assist with flooring adhesive , follow the manufacturer installation instruction

I've never heard of wood splitting because it was glued and fastened.If you use the correct glue for wood flooring it is elastic to 300%. I suppose it could but then that might fall into a kiln drying or other defect in the wood.

I like Ken Fishers idea of using engineered. Much more stable.

Thank you all for replies.

I am locked in at this point on the solid.

I'd prefer not to do full glue down because of the mess. I don't trust myself to not make a disaster of it.

I'm planning to use the fastener plus adhesive on the back side for my 2nd floor. I need to pick an adhesive for it.

For the first floor (which is small hallway and opening at bottom of stairs - about 75 sq ft total) I'm still on the fence. It is over a finished portion of the basement. There is a dehumidifier in the basement to keep humidity to 45% or lower. It is not temperature controlled. I'm wondering if this would benefit of still having some sort of vapor retarder, whether I rely on mechanical fastener only with vapor retarder (because the area is small overall) or doing full glue. If I don't need to worry too much about the retarder I would do the same process as second floor.