Underlayment question-- "extending" existing underlayment fastener and type

cbrc5eric

I knocked down 2 walls (you may have seen my other thread about a week ago) in my living room/dining room to form 1 big room. I have decided to put down vinyl or Duraceramic in this area. Admittedly I don't know much about flooring so I've done quite a bit of research. Before I get too far into this I wanted to ask here. I needed to extend the underlayment area to where the walls used to be.

Details:
The house is older so the sub floor is 3/4" planks run diagnoally. They are in good shape. Where there's no hardwood floor there is existing 5/8" underlayment also in good condition, appears to be held in place by a combination of ring shank nails and roofing nails.

The "patch" areas are 8 ft x 10 inches and the other is 7 ft x 7 inches so not too large.

Issue #1) The rating of plywood:
I used 5/8" sheathing plywood (for roofing) from Home Depot not knowing there is underlayment grade plywood. Now I know better but for my relatively small patch area, should I bother to redo this and buy the "right" stuff or will my patch work?
As you can see in the pictures I havent fastened them down completely yet (no glue), just screws which I will patch over. The height match is great. Which brings me to:

Issue #2) Fasteners for the underlayment:
There's so much info I came across my head is spinning. The consensus I get is- screws are usually not used especially in industry standard 1/4" thick plywood but keep in mind this is 5/8" thick and not a whole sheet of plywood.

I have a crown air stapler with plenty of 1/4" staples I plan to use for the rest of the joints (every 4") but I'm now reading 1/4" may not have the holding power for underlayment thicker than 1/4". What should I do?
Any advice?



Before shot:

oh'mike

The question is this---what's going on top of the underlayment?

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cbrc5eric

Vinyl or luxury vinyl (Duraceramic)- havent decided on brand/pattern/color yet.

oh'mike

The sheet goods require a very good surface---consider adding 1/4 inch Muli-Ply over the top---

If that's not an option--use Ardex Feather finish to flatten any uneven places.--Mike--

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cbrc5eric

Alright makes sense. I'm going to pull out that underlayment I did and redo it with the right stuff even though this stuff would probably be fine. I'll have to buy another sheet for $20 but I'd rather have it done right and chalk it up to a lesson learned I had to call around to several places but finally found one local lumber yard who has 5/8" in underlayment grade.

I don't want to put any additional height so I'll do the feather finish. I looked left and right for Feather Finish found a few places but they're all contractor supply houses (so they're kind of out of the way and have limited hours). Called Ardex tech support line and they told me that it's the same product under Henry 449 and Lowes and Henry 549 Feather Finish at Home Depot.

Now- for transitioning from the hardwood to the vinyl is it customary to use a perpendicular wood piece to "trim off" the hardwood surface? I was at a friends house and saw this done where their floor transitioned to vinyl- though it was through a door. Since my floor is on an open room I thought of just having the hardwood stop and the vinyl start.

oh'mike

The wood/sheet goods transition--Yes--Picture frame it---

The butt ends of the flooring should end into another board.

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cbrc5eric

Makes sense. Dang, I thought I had it all figured out, now have to regroup and put the picture frame in (is the right terminology the "feature strip"?) It should make the transition look better though. Particularly where the wall ends, it will (hopefully) look less like I knocked out 2 walls :D Now I plan to use 3 strips of 2 1/4" board to bridge the gap to the wall, where the vinyl will take over, then do a perpendicular board of the same color to create the frame.

Now I'm kicking myself I routed off the "tongue" of the parallel hardwood floorboard when I put the 5/8 underlayment in, I suppose I could just make it a "groove" now. EDIT Either that or I'll just replace that board entirely and make it part of the (now even thicker) frame since that piece has some damage and the tongue will be on the wrong side for the air nailer.

Which brings me to some hardwood floor questions:

1) When making the transition for the perpendicular boards- what side should have the tongue and which the groove? Or, does it not matter? In other words, should I "tongue" the butt ends of the existing floor? Or groove it? EDIT- after doing some research looks like I should tongue the existing boards, that way the groove of the perpendicular board will be in the right position for the air nailer.

2) At the 90 degree turn in the frame, I can either Mitre 45 degrees it, or stagger it with the pieces interlocking (remember, I'll have 3 strips to create this frame). Any recommendations?



I have found a fairly close, slightly darker match to the flooring that's readily available prefinished at the Home Depot that should make a good frame.

oh'mike

How your corners meet is a matter of style and personal taste---Miter or butt is your choice.

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HardwoodFloors

If you use a cabin stagger you won't have to worry so much about overwood or splintering like you might with a 45

cbrc5eric

You guys probably think I'm changing my mind like I'm changing my underwear I've now moved to a different option yet again and have more questions. After pulling the existing hardwood planks preparing for the underlayment, I was able to identify the wood and grade used based on the information printed under the planks. Turns out I have Appalachian White Oak, Clear Grade. I took a few samples to a local hardwood floor wholesaler/supplier and they had Select or Better white oak in stock from Middle Tennessee Lumber. Lumber Liquidators had Select grade white oak too but the lengths were 1-7' where the other flooring is longer and better match the longer planks of my house.

My plan now is, I want to stagger the existing floor with the newer unfinished white oak, then have the entire room (possibly the entire house) professionally sanded and restained. I'd cut out the existing planks at random lengths so it doesn't look like the hard line it has now. I would hope with this approach it should match reasonably well. Fortunately the tongues are pointing towards the unfinished part so at least they are going the right direction

My question now- when doing the joints between the existing floor and the newer floor- can I just butt joint them? Or should I try to router/chisel out the top and the bottom to create interlocking joint? I'd imagine trying to recreate the tongue groove on an installed floor would be fairly tricky due to the rounded edge of the router bit and the potential of runining the adjacent boards (not to mention a flooring T&G bit set is over $100 like the grizzly C2307).

Picture speaks a thousand words: