Built-in Bookcase

[garfunkel]

Hi Everyone,

I'm looking some advice for building a bookcase around a bay window.

I've attached a picture which may explain better.

I'm currently thinking it has to be built in three sections: left, right and middle. Question would be how do I secure the middle section given it'll be above the opening and will be in my case 2 metres in length (i'm building out of 18mm birch ply).

Any help would be appreciated.

Thanks

 

[dzj]

A hefty beam behind the crown molding would carry the middle section easily.
The colour of that floor hurts my eyes.

 

[garfunkel]

Thanks for the reply - won't be copying the carpet

Re the beam - do you mean resting it on top of the two sides spanning the gap and then screw the middle case to it?

 

[dzj]

Yes. Coupled with plywood backing there wouldn't be any problems regarding sagging.

 

[Adam9453]

+1 for above method, just make sure when calculating the size of the timber for the beam to work out how heavy the middle section will be, particularly if you plan to load the shelves full of heavy books.
Small scale glue lam beams could be better as they're lighter but very strong.

 

[acewoodturner]

How about a couple of French cleats at the back of the middle section. Dont have to be more than 30mm thick. I have held up a large light box and display unit for a commercial customer which weighed about 120kg at least and the cleats were screwed into breeze block. That was 6 years ago and it is still fine. This was a vastly over engineered job as the public could get in close and we obviously didnt want it falling off the wall.

Mike

 

[Monkey Mark]

How wide is it going to be in total?
You could make a short left and right side then make the top section to go right across the lot.

 

[garfunkel]

Total about 11 foot (left ~3ft, middle ~6ft and right ~2ft).

Boards I have are 8 foot max in length.

 

[garfunkel]

I had thought about the french cleats as they would be secured to the brick wall. Could they be made out of the 18mm birch ply or would that be a bit light?

 

[acewoodturner]

Its not the weight factor but the the strength factor you should be looking at. As they are totally hidden from view you could make them out of anything. Cls is fine. About 30mm would be ok as you can locate them in position easily enough. I ran mine nearly the full length of the light box and it also helps to prevent any sag.

Mike

 

[Adam9453]

bit of a PITA though to get everything to line up bang on at the front if you're using french cleats at the back. Personally I would hang it from beams across the top of the side bookcases, then mount a plywood board to the wall behind the centre section which you can put as many fixings through from the front once the middle section is in place. It saves a lot of aggro in trying to get those shelves to line up exactly.
I'd say two beams across the top, board behind and plenty of screws through the back and into side bookcases will be plenty strong enough.
If in doubt, weigh the books to go in the shelves and use the sagulator to calculate the size of the shelf required, will give you a good idea how strong the level of support needs to be.

 

[garfunkel]

Thanks for the replies. Lot of different methods to consider, had also seen someone use a number of L-shape brackets which are hidden in the end to support the middle section. Have a lot to think about before I get to work!