Lower cabinet upper bookcase flanking window seat built-in construction questions

You’re not going to want to make the cabinets tight to the walls unless you check to make sure they are plumb square and so on, because if they aren’t, you’re going to run into problems.

-- The mark of a good carpenter is not how few mistakes he makes, but rather how well he fixes them.

So how would you construct the back of the cab that hits the wall? Maybe inset the back 1/2 inch panel a 1/2 inch to give the sides ‘wings’ and then that will allow you to scribe the sides to the wall? Or don’t do that and just square and level your box to the wall and then add trim where the side hits the wall? I already am assuming I will need to scribe the side of the face frame that touches the side walls.

Well for one, I don’t think a window seat is going to work very well w/ the shutters. If you have the shutters open then sitting in the window seat is going to be awkward and if you close them then you can’t see out the window. Maybe it is just me but I would replace them w/ mini blinds or shades. Second, you are going to have to build the cases it so you can scribe them to the wall for final fitting. 1/2 inch plywood is fine for the back but I wouldn’t rely on it to attach the whole thing to the wall. Somehow I would incorporate some sort of structural members for screwing the whole thing into the studs in the wall. The cases are going to be heavy, books are heavy, the construction should be beefy to support it all. Have you thought about the shelving? A 47” span for bookshelves is quite long and will have to be thicker that 3/4” plywood or they will sag terribly under the weight of books. I once built a built-in bookcase that had a 44” span and I used pine stair tread for the shelves. Stair tread is about 1” thick and that has worked fine.

-- Bondo Gaposis

I have thought about the shelving. The actual shelves will be approximately 41-42” wide. I was planning on using solid 1×2 banding on the fronts, and from what I’ve read, that should make them strong enough to have minimal deflection. Am I missing something here?

Regarding the base cabinet. What if I just used 3/4” all the way around, top, bottom and sides? Would that be beefy enough to support a bookshelf?

How do you guys build the back of your cabinets so that it can attach to the wall? I’m thinking you probably build the box and then attach it to the wall and trim out the gaps?

Good explanation of your plans, noone.

I’ll address your structural questions.

In the stock image it looks like the bookshelves stack right on the structure of the cabinets below—so the strength of the top is not an issue.

re: bookshelves: are they adjustable or fixed? Fixed, I think the front lip will keep them from smiling at you, but adjustable, I’d want lips front and back for that distance. All-veneer ply would be stronger than that with MDF substrate under the face veneer.

Your half inch back is unnecessary. Standard practice is 1/4 (or 5.2mm) back material. Attachment to the wall is through a nailer that appears at the top and bottom of the carcase, minimally 2.25 inches, easier if it is 3 or so.

If you want a flush fit to the wall at the window edge, you can rabbet the side of the cabinet there deeper than the 1/4” and scribe that bit of ply away as needed. Simpler designs just apply the back to the sides and then use 1/4×3/4 scribe mould to cover the gap. In that you’re doing paint grade, this plan, well caulked, will yield a nearly seamless look and is much easier that scribing the side of the carcase.

I sense that you have the shop skills to execute the casework, but a lot of advance thinking about the installation will be necessary.

Will you sit this on the carpet? How will you deal with the tack strip, the receptacle and the existing base (at the sides)?

One other question: The depth numbers seem large. Bookshelves are typically 10 – 12” deep. Do you collect art, architecture or railroad books? Those need a little more space.

Finally, I sense you are concerned about the cabinet being tight to the wall. It actually takes very little force to pull them there and keep them, provided the base cabinet is sitting firmly on the floor and is true.

Kindly,

Lee

-- "...in his brain, which is as dry as the remainder biscuit after a voyage, he hath strange places cramm'd with observation, the which he vents in mangled forms." --Shakespeare, "As You Like It"

Regarding the depth of the bookshelves, the wife wants to be able to put certain size Pottery Barn baskets on the upper shelves, so that is why I want the usable shelf depth to be 14”. :) I was planning on those shelves being 3/4” Birch ply, with 1×2” solid banding on the front. From what I’ve read, that should be just fine with little to no deflection. No MDF will ever be used on any project in my house…. :)

I was only able to find 1/2” birch ply and not 1/4” at the Depot. I saw 1/4” Sandeply, but I didn’t like the feel of that compared to the 1/2” birch ply, so I just went with the 1/2” birch ply. And I didn’t like that hard board stuff either, at all.

I guess it sounds like it may just be easier to make the entire back out of 3/4” birch ply (it only costs 3 bucks more a sheet than the 1/2”), because I want the interior of the cab to be perfectly flat in the back. Then I can make a 3/4” box and attach that to the wall, then use scribe mold for where it meets the back wall, and then scribe the side of the face frame that hits the side wall. Then caulk. Seems like the way to go for my first cabinet making foray.

I was planning on using 3/4” fins to raise the cabinet up to the height I want it to be so that that the reveal above the 5 1/4” base would be exactly 2”. My face frame bottom would extend all the way down past 2”, say 3” and then I would just put a 3/4” thick filler strip underneath that to the floor. This way the 5 1/4” base would work nicely. The cabinets will be shimmed and installed on a concrete subfloor. I will be putting wood floor in afterwords and will account for the wood thickness when I build the height of the cabinet. I want the counter top to be at exactly 36” from the wood floor, so that will make my cabinet sides 36” + the height of the wood floor.

Again, is it okay to use a 3/4” thick top only for the top? Will this be strong enough for the upper bookcase? I was planning on having a 3/4” birch ply top screwed and glued in between the sides (i’m using Kreg pocket holes on this project), and would then trim it out with some nice chunky base cap to make the ledge. Then install the bookcase on top.

As for electrical, I will relocate the outlets to the insides of the cabinets. I am also am planning to twist into the electrical up in the attic to have switched upper bookcase lighting as well.

Thoughts?

I like the fact this is your first project for your home, you have obviously put a lot of planning into it and I hope it goes well for you.
The thickness of the top really doesn’t matter – as the load from the top will be transfered from the sides of the top part to the sides of the base cabinet.
One little tip for you is to bevel the inside of the side pieces where they scribe to the wall, it will be much easier to plane into shape.
Is this being painted in the workshop or in situ? If you are installing it already painted, make sure whatever finish is fully dry/cured. Place a sheet of thin card on the top before putting on the top piece to protect the paintwork. Get it ready to fit and slide the card out.
Before you start, make a note of how level the floor is and whether the walls are plumb and corners square – just so you don’t have any nasty surprises when you come to fit it. Oh, and if you’re using a pencil to mark that final fine scribe line on the job, wrap a bit of masking tape round the pencil to stop it rubbing ‘pencil paint’ on the wall.

-- Never trust a man in winklepickers

Ok, my first carcass assembly went pretty well. I measured everything perfectly, all pieces. One side was off by maybe 1/32 – 1/64 in length. That was it. All other pieces were perfectly sized. I glued and screwed everything but the face frame and it seems that everything is not as square as I would have thought it would have been. The top is perfectly square. The bottom, not so much as you can see in the pictures. I spaced the floor out perfectly from the bottom of the side using a jig. When I measure the top surface of the bottom to the inside top edge on both sides, it’s exactly the same front to back, top to bottom. Same with the bottom, bottom edge to the bottom of the side that touches the ground. Perfect measurement from front to back and top to bottom.

I’m thinking this may just be the flex of the wood and that the face frame, once installed, will straighten everything out, at least i’m hoping. When I measure diagonally corner to corner, it’s off by about 3/16.

I also still need to install support fins across the bottom as well. (and doors)

Comments?

Any comments? Tell me, i’m worrying too much….. I guess I need to check the squareness of my kitchen base cabinets with a framing square for reference…..

Hi Noone
It looks like you just have your top and bottom butted inside the the sides,even if there screwed together I don’t think that’s strong enough. I like to have at least a rabbit on top and a dado on the bottom. If you have all your measurements equal when you put the back in assuming your rabbiting the back in that should square the case up.

-- W James Brokenbourgh Custom furniture maker http://artisticwoodstudio.com/

Hmmm. I was planning on going backless. I figured the nailer on the top would suffice along with the face frame, since i’ve seen cabinets with that luan crap stapled on the back with only a nailer at the top. Did i figure wrong? I didn’t build rabbets into the side panels so I’m not sure what I can do now that it’s all glued and screwed.

I’m a overkill guy,it’s just that books are very heavy. I know Ikea and others build book cases the way your doing it so if you feel good about it thats up to you. If you decided to put a back in it you could use a rabbiting bit and make a rabbit around the back edge even when it’s together but it would take a little chiseling at the corners.

-- W James Brokenbourgh Custom furniture maker http://artisticwoodstudio.com/

Will the face frame strengthen and square up the box?

Yes it will how do you plan on attaching the face frame and how wide is the material your using.

-- W James Brokenbourgh Custom furniture maker http://artisticwoodstudio.com/

I just reread you post it looks like your going with 2” face frames that should help make it stronger. I noticed you have a gap in the middle of your framing square ,that might be from your ply having some bow in it,that could account for your out of square measurement your getting. Have you checked your square to make sure it’s square?

-- W James Brokenbourgh Custom furniture maker http://artisticwoodstudio.com/