Ship-lap

[Jack Frederick]

This bookshelf I am making has a 29” back panel that will use 8 3.75” x 55”x.048” ship lapped boards inserted into 1/4” deep dadoes all around. How do I keep these boards from rattling around. I have been thinking about dropping some wire insulation that I strip off some thin wire as kind of a softener top and bottom. It is a bookcase and will be full so quite heavy, but still, am I making a mountain out of a molehill? Much obliged for any direction here.

[Ronald Blue]

Can you use these? Seems like the same issue.

https://www.rockler.com/space-balls-raised-panel-door-spacers

[Bill Dufour]

It will only rattle during a quake. Or is the house and bookcase so flimsy it will rattle when people walk by or a truck drives down the street. Do your dishes rattle in the cabinets now/
Bill D

[Christian Hawkshaw]

I usually just use rabbets and screw the boards in as opposed to floating as a panel. I use dimes to space them, and orient the screws such that movement is still allowed. You can add screws to each fixed shelf as well as the sides. Here bookcase that I just finished where I screwd in the shiplap boards.

https://sawmillcreek.org/showthread.php?298050-Shelf-for-the-Office&p=3195570#post3195570

[Maurice Mcmurry]

How about 16 tiny nails or headless pins installed from the back?

[Jay Aubuchon]

If your assembly sequence allows it, you could also put a little glue just in the middle inch or so of each board.

[Andrew Seemann]

If the fit in the dado is fairly tight, you may get enough seasonal cupping in the boards to more or less friction fit them in place, while still allowing for expansion and contraction.

A nail or pin from the back through the dado into the boards as mentioned above will also do the trick, and it is safer to do now in summer than in winter when the boards have shrunk.

[roger wiegand]

Most of the old bookcases I've worked on that were made in a similar way used a few small nails.

[Derek Cohen]

This is taken from an article (http://www.inthewoodshop.com/Furniture/ApothecaryChestShiplappingTheBack.html) I wrote ...

Shiplapping is the joining of boards using an overlapped rebate. The advantage of this is to allow for movement while presenting an outward solid and sealed surface.



http://www.inthewoodshop.com/Furniture/ApothecaryChestShiplappingTheBack_html_704a3c1a.jp g



The rebate is on each, but opposite sides of the board. In this case, I have made the rebate 10mm wide. This will allow for an overlap of about 7-8mm.



Here I have made use of sections of Black Walnut that would otherwise be considered offcuts …



http://www.inthewoodshop.com/Furniture/ApothecaryChestShiplappingTheBack_html_m7f9124d.jp g



The boards are 6mm thick, and each rebate is just 3mm high …



http://www.inthewoodshop.com/Furniture/ApothecaryChestShiplappingTheBack_html_m2489acd8.j pg



The boards are fitted into a rebate running around the back of the case.


The boards could now be cut to length and fitted. The rebate gap between boards was set with a spacer …



http://www.inthewoodshop.com/Furniture/ApothecaryChestShiplappingTheBack_html_50d97b69.jp g



No glue is used as the boards are free to expand into the gap. A single screw holds them close to the overlap …



http://www.inthewoodshop.com/Furniture/ApothecaryChestShiplappingTheBack_html_m2d1d9e99.j pg



Done …



http://www.inthewoodshop.com/Furniture/ApothecaryChestShiplappingTheBack_html_m6eb6fa60.j pg

Regards from Perth

Derek

[Phillip Mitchell]

I have done plenty of shiplap in furniture, interior woodworking and exterior work (siding) and I pretty much always do as Derek illustrates above. I am installing some 1x8 clear Douglas fir shiplap on my front porch currently and have a single line of screws (8’ tall boards) that’s about 1 1/2” in from the right edge that overlaps the open lap of the previous board. This holds the board on/tight but doesn’t trap its seasonal movement. In this case I used 1/8” spacers to establish the expansion gap between edges/boards.

Same would apply in furniture or interior work - it generally becomes a question of how you want to deal with fasteners and if there’s any visual or aesthetics restrictions on that. For a cabinet back, I see no issue with a single, well placed quality screw at top and bottom of each course as Derek shows.

[Warren Lake]

I wouldnt do ship lap backs. I did it once and decided not again. You have two rabbets and if one board wants to move forward or back it can. A tongue and groove will keep stuff contained.

Derek nice work as always.

479627

[Halgeir Wold]

Lots of commercial products around, - and today lots of flatpacks, that use shiplap og other 1/2 panelling as backs.... they all use small nails to hold the boards in a rabbet...

[Bradley Gray]

I prefer spline and groove.

[Bruce Page]

I’ve only done ship lap once (actually spline & groove) and probably didn’t do it right. I screwed each piece into a rabbit. We don’t have many earthquakes around here, but I have never heard any rattling.

[Sam Goldsmith]

I typically attach backs with either GRK trim head screws or cut nails, depending how I'm feeling and if I'm going for anything more traditional. I also like to nail into the shelves, I'm not sure on your overall design if your shelves are fixed in dados or not, or how thick they are, but it will help resist sag over time and add some strength.
Fixing the back boards will also keep your gaps consistent and visually appealing.