Attaching Bookcases to Countertops
We currently install the lower units, put on and scribe the countertop to fit, then put the bookcases on the countertops, screwing them onto the wall and each other. We like to secure the cabinets to the countertop as well for strength and to avoid any small gaps. We would just screw up into the uppers/bookcases, but the ends of the bookcases always are in line with our fillers below, so we can't get access. We are not using bottoms on our uppers/bookcases. This would make things easier, but we like to keep the countertops open and avoid the small step up to a bottom shelf, particularly with narrower shelves/countertops. Most of our designs have called for the bookcases to be several inches narrower than the cabinets below, so a bottom shelf really takes away from the open countertop space. We have given thought to using splines or biscuits as locators, but inevitably the cabinets have to be moved around to fit the wall or opening and the biscuits that worked perfectly in the shop would probably not work the same with the walls in the field. We have also considered breaking the countertop up into smaller pieces and attaching the bookcase backs to the back of the countertop. But this is difficult to finish, more joints in the countertop, and if the walls are out of whack like on our last install, we would never get our cabinets and countertop joints to align.
On our current project we are going to get the countertop set up, then secure blocks down into the countertop in the gaps behind the fillers on the bookcases, then secure the bookcases to the blocks, effectively locking the shelves to the countertop. The backs themselves are always another issue... We use 1/2 backs and have tucked them behind the counter, put them in a rabbet. Still no "perfect" method there, either. We were just going to try and keep them flush with the bottoms of the bookcases and let them sit on the counter for the next job. Anyway, that's our dilemma... Anyone out there doing stuff differently? Some time-proven method that makes for quick install while still affording you some flexibility in the field? Am I giving this too much thought!?
If your primary intent is to eliminate those unsightly gaps and you cannot access the bottom edge of the bookcase sides, in the past I've used Selby keyhole fasteners at that junction. By using these you can do all your scribing, etc. and then slide the bookcase over the Selby fasteners and wedge the bookcase down onto the countertop. You need to see the fasteners to fully understand how this would work. Get a hold of the latest Selby catalog and look for item # K 2094, page K 9.
The first response has it right. Attach the upper sides from under the top. Forget the groove for the back. Attach the backs (on-site). If the wood grain on the top is kept (front to back), then making multiple sections for long pieces will get it done easier. On a long unit, you can brace the center sections to the wall and leave out the center panels for a nice, long, unobstructed top.
I too have struggled with the exact issue you describe. My solution to fastening the uppers to the counter was to make the upper section case 1.5" narrower than the base case. This offsets the upper sides from the base sides and allows a screw to be driven from below into the bottom end of the upper sides. I also insert a filler between the upper sections equal to the width of 2 base section ends. For example, if the base sides are 3/4" thick, then I use a 1.5" filler between the upper sections. This allows the upper units to be fastened side to side as well. The face frame that fits over the face of the case then hides the filler and everything looks like a standard install. No one is the wiser that there is a gap behind the face frame. Getting the back of the cab to fit tight to the top is a tricky proposition at best. The only sure fire way is to scribe the bottom of the cab if there is a gap. We try very hard at assembly to insure that the back and sides all end up perfectly flush at the bottom in an effort to minimize the gaps. One other helpful trick is to pocket screw the back side of the face frame at the bottom of each leg where the frame meets the counter. This allows the frame to be sucked tight to the counter.
This might help... Cut the finished and stock panel same size. Pocket screw the stock panel side and back and then apply finished panel.
I do this style of built-in cabinets all the time. The method that I finally settled on is as follows. Design the cabinet as one solid unit. All the sides run in the same plane to give those nice lines. Add a decorative countertop edge that wraps all three sides (front, side, side). Construction is a two-piece cabinet. Basically, the lower that looks like a standard base cabinet with stretchers. The upper is a bookshelf attached to the countertop. The countertop edge is 1 1/2" wide so it hangs 3/4" down. This lip covers the base cabinet. You can screw your bookshelves from the bottom of the countertop or biscuit, or pocketscrew. Whatever floats your boat. Make your rough countertop (minus the edge) 1/32" bigger than the base cabinet. The metric plywood usually accomplishes this for you due to its thinner width. Make sure you keep the 1/2" back fastened flush to the bottom of the countertop, so you can slide the upper over the lower. I've done 8' long walk-in closet cabinets in this manner.
Are you nailing on your countertop edge afterwards? Am I following you correctly? If so, just putty the holes? Or are you talking about securing the countertop to the bottom of the bookcases? We have toyed with that idea, but rarely could we do that... The last run of cabinets we did was 11 feet, and we have done work in apartments where everything has had to fit in an elevator as well.
Which hole would I putty?
Yes, I apply the edge in the shop, usually pocket-screwed and glued from the bottom of the countertop. This basically leaves a lip of 1/4" to 3/4" depending on your countertop edge profile.
I build the two units completely in the shop. I staple a couple of pads under the countertop to protect the edge. Some people call this a "high hat." I've done both white Crystalac as well as Hondu mahogany. I'm telling you this method is just the crackers. I've tried all the other ways mentioned and they all have easy mistakes. Installation is a synch. I scribe the base cab first. Then slide the upper on to the base. Then scribe the sides and top if it's a floor to ceiling. Pull the upper down and make your scribe cuts. Place the upper on the lower and raise your cabinet levelers and push that beautiful piece of work right through the ceiling.
I personally, when applicable, will slide the countertop out and screw the upper cabinets down from the underside of the top. You would need to scribe the cabinet to the wall before you do this.
I've built them with and without the step up the bottom.
They do sell the veneer adhesive caps that you can finish to the same color as the unit you're doing. They tend to work well when feasible. They are real wood veneer. Hafele and Baer Supply sell them.
I am glad to hear other people have struggled with finding a good solution. The Selby fasteners are good but require un-forgiving precision. Almost without exception, I pre-attach the counter to the uppers (backs are affixed to counters also) with every potential concealed area greatly relieved to prevent "bottoming out" as you scribe the most visible cabinet-to-wall stiles. The countertop nosing obviously hides the joint between conventionally built lowers and this entire open bookcase and pre-attached counter unit. This has worked well for us in 99.9% of applications.
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