I am planning my first hardwood install for my house. It will be 4 1/2 x 3/4 Engineered Walnut on the main floor running from the living room into my kitchen. The subfloor is 5/8 OSB. I need to figure out a couple of issues befor I can start.

First, I have carpet in the living room and vinyl in the kitchen. When I pulled up the carpet I found several small l-shaped metal plates placed every few feet along the main wall. The plates have a single screw into the subfloor and run behind the base molding, which I have not removed and was not planning on it. The plates also seemed to be screwed into the wall behind the molding. I am not sure what the purpose of the plates are but I am not able to lay the floor with them there. They are thin scrap grade metal and are only held down by a single screw so its hard for me to believe they are load bearing. Can someone please let me know what the purpose of these are and if it is safe to remove them. I would like to keep the base molding in place and am thinking of just cutting them off. I have posted an image of what I am referring to.

http://picasaweb.google.com/mroth95/Floor#

Secondly, I have found that there is 1/4 plywood underlayment under the vinyl in the kitchen. As I would like to have a continuous run and not a transition from the living room into the kitchen what is the best soultion here. Is it possible to stagger shims up to the 1/4 gap, how difficult would that be? Would it be better to lay 1/4 plywood underlayment in the living room to bring both rooms to level.

Thanks

Those are hurricane straps. Their purpose is the re-enforce the exterior walls from being blown out in a hurricane. That is one purpose anyway. They may have been installed for another purpose. Strapping is typically required by local codes. Builders would not install it if the local codes did not require it. I suggest not cutting them off, even though if you do, no one will know but you. In situations like this, I will under cut the wood flooring to allow it to be installed over the plate. Just right where the plate is.



The plywood the vinyl flooring is installed over is an underlayment for the vinyl flooring. In this case, one typically removes both the vinyl and the underlayment down to the subfloor. That way, all your installation will be at the same height. Hope that the plywood underlayment has not been glued down.



3/4" ENGINEERED??? Are you sure? If so, quite rare. 5/8" OSB subflooring??? Again, are you sure? Is this a "mobile home" ?

More and more manufacturers are producing engineered flooring in a 3/4 inch configuration. Vintage makes what they call "solid sawn" which is a three layer product; top and bottom are whatever the floor is to be, center third is narrow strips of same wood laid across the linear direction.
A most amazing product for stability, and little difference in cost. Since the top layer is equal in thickness to the wear surface on a solid product, the consumer (and the flooring contractor) end up in a win-win situation.
It has been so sucessful here in our tremendously variable climate that both we, and Vintage are switching to this format wherever possible. It is warranted from 30% to 65% relative humidity, and even outside of the range the floor seems to remain trouble free.
One of the first apps we did with the floor was a 5 1/2 inch hickory in a seldom occupied condo. The apartment was vacant the entire first winter and cupped so severely from lack of humidity that it looked to be a sure thing we would have to replace it.
The manufacturer's rep and I decided that since it was still unoccupied, we would try to restore the floor. We put two big humidifiers in place and the interior decorator (who alerted us to the problem in the first place) would fill them up every morning, and I would do the same every afternoon. Within two weeks the floor had flattened right out and we ended up only needing to replace about 7-8 boards in a 1500 foot install; due to fractures in the surface "veneer".

Owen's, as well as others, have been making solid sawn veneers bonded to quality backers for years. However, I haven't seen it in a full 3/4". Mostly I see a 3/16" veneer bonded to a 7/16" backer, creating a 5/8" thick floor. I do agree this type of floor is excellent. It is not cost effective compared to an unfinished solid in my area. The Owens is usually 2 to 3 x the cost of a solid, depending on the species. However, when comparing gluing down Owens to concrete as opposed to installing a plywood substrate over concrete, then nailing down a solid, the Owens approach becomes much more comparable in cost.

Ya I have heard of the Owens product, but not much access to it here so we work with local products. The Vintage "solid sawn" is a full 3/4 inch, comprised of three 1/4 inch layers of the same type of wood, as I described earlier. A most remarkable product, and warranted even below grade, although it is essentially a solid (sorta). The use of three layers of wood, rather than one, bonded to a plywood substrate, has proven itself very well in our extreme climate.

I believe Capella, had ¾ engineered, in a prefinished.

Actually, yes it is made by Capella. I ran into issue when I found that the floor joist run length wise through the house when I wanted to run the flooring length wise with the natural light. Even with a thick hardwood I am worried about running the boards the parallel to the joists. I am planning on removing the underlayment and stiffining the subfloor with 1/2 plywood throught.