Building a New Roubo - Split Top v Standard

[Joshua Lucas]

Let me make an argument in favor of a split top, especially if you are going to use a green slab for the top.

I bought a 3.5" x 23" x 7' (well, 10', but 3' got used for the legs) white oak slab about 5 years ago for my bench top. At the time it had been air-drying for about a year and was around 25% moisture content. I let it continue to dry for another year, which is to say that's how long it took me to get around to building the bench. By then it was probably 20% MC. Initially I had planned to make a solid top, but in the intervening year it had cupped considerably so that the center of the slab was probably an inch lower than the edges. I dealt with this by sawing the slab in half and making a split-top bench.

When I built the bench the split was a bit under 1.5" wide so I made a filler out of a 2x6. In the four-ish years since then the gap has grown to a hair over 2" - more than half an inch of movement. If the top had been solid (ignoring the issue of the cup) it would have either warped the base considerably or, more likely, split badly down the center. However, since the top is split, the only problem is that I need to make a new filler.

I don't use the split for anything - clamping, tool storage, or otherwise - so I wouldn't miss it if I were to glue in the filler. I probably won't do so though because while the top is mostly done moving, it may never completely stop.

As far as keeping the tops coplanar I haven't really had an issue. I re-flattened it once a couple years ago and haven't needed to since, though it probably wouldn't hurt to do it again. Of course any slab top, especially a green one, is going to need flattening every year or two. It probably helps that my tops are from the same slab and are mostly quartersawn.

In short, I'm very glad I went with a split top because green wood moves a lot.

[Joel Gelman]

In case you did not see this thread...

https://sawmillcreek.org/showthread....-top-workbench

[Tom Bain]

In case you did not see this thread...

https://sawmillcreek.org/showthread....-top-workbench

Joel — I have seen that bench and it’s pretty incredible. Probably a bit overkill for my needs, but may borrow some ideas. I kind of like his half-split, half-not approach to the top, although it does negate the benefit of a split-top if one ever needs to move it.

[Ron Brese]

I don't think you can go wrong with either bench top configuration. The only problem I see is that you've had BenchCrafted hardware on a prior bench and I think you will find that other hardware just won't give you the ease of use. Sort of like driving a basic bare bones car after you've had a Cadillac.

Ron

[Anuj Prateek]

I'll suggest going with single slab (non-split) bench. Whenever I'll build a new bench I will stick with single slab.

I built split top Roubo using construction lumber. It's pretty stable. Had to re-flatten it 3-4 times in last 5 years.

However, the gap (between the two slabs) and the filler has not proven useful for me. I rarely use the filler as planning stop and instead use alternates. Same with using the gap for clamps. In case of former I use LV planning stop that goes in dog holes. And, in case of later I find holdfasts much easier/faster than clamps through the gap.

Overall, looking back, split top brought complexity to the build w/o adding much value.

[George Yetka]

Can you lop your last bench instead of building new?

[Mike Brady]

Here is another take on some of your questions; based on my twelve year's experience with my current bench:

Like Tom, above, I employed a split top design for two reasons that were important to me: I like a tool well. The well holds the hardware that I often use such as bench dogs and some measuring and marking tools. Most importantly (I never anticipated this), having the bench top in two pieces makes handling of the ash bench components just that much easier if you ever have to move your shop. Think of it like the story of the guy who builds a canoe in his basement and then can't get it up the stairway. My bench would not, in fact, fit into the basement stair well; yet I assembled by myself it after a move a few years ago.

The bench legs and frame have bolted components as well; for the same reason. The two leg assemblies are an H configuration with glued M&T joints. They are draw-bolted to the two rails.

Good luck on your build! A good bench is a game-changer.

[Thomas Crawford]

I've had a regular Roubo going on 15 years now, based on the first book. I can't think of a single time I've wanted the split top or had any issue clamping things or needing a planing stop that I couldn't make with some holdfasts. Always just seemed like a place to collect dust and shavings. I'm planning on building a new one this year, hopefully 10 feet long, and will do a single laminated slab again. But to each his own, I built it before I really built anything else so I'm sure my style just adapted to what I had.