Duncan Brown
06-10-2020, 9:08 AM
I have an 80" x 21" live-edge slab of English elm from Berkshire Products that I'm installing in my basement as a bar top. The slab is 1.25" thick, is flat sawn, and the slab will be installed bark-side down. The slab was vacuum kiln dried to between 6-8% by Berkshire and has been sat raised up on 2x4s in the basement for a few months to acclimate to the humidity level down there (about 55-60%). It's been sanded to 80 then 120 grit and will be finished with Rubio Monocoat.
The slab has no cupping but it is bowed down its length with the center raised about 0.5" higher than the ends. From reading the posts here, it seems like the best advice is "do nothing," as this level of bow is not terrible and the slab is too thin to level with a router. The bar top feels level and you only really notice the bow when you look under the bar and compare it to the pony wall that is dead level. The bow means that the slab only sits on the end two brackets, but since they are Centerline brackets rated for 100lbs each and the slab weighs 50 lbs tops, that should be fine.
I was hoping to get some advice from the experts on the following questions:
1. Is my "do nothing" approach reasonable? Posts here seems to suggest that 0.25" of bow over 7' is entirely expected and that even the 0.5" bow that I have is not too much to worry about.
2. Should I add a shims so that the slab also rests on the middle two brackets or just leave it alone?
3. The brackets don't have screw holes, so to stop the slab tipping when someone leans on the edge, I am planning on attaching a 4" mending plates with #8 or #10 screws that sandwich the bracket between the mending plate and the slab. I'll do this with the two end brackets, since they are the ones that make contact with the slab. Since the slab will be able to move relative to the brackets and will only be fixed along its center line, I think I'll be fine for expansion across the grain and any small movement along the grain. Does this sound reasonable? I'm trying to avoid drilling into the 0.5" inch steel bracket to make a slotted hole as I don't have the metal-working gear to do this.
Thank you in advance for any advice.
The slab has no cupping but it is bowed down its length with the center raised about 0.5" higher than the ends. From reading the posts here, it seems like the best advice is "do nothing," as this level of bow is not terrible and the slab is too thin to level with a router. The bar top feels level and you only really notice the bow when you look under the bar and compare it to the pony wall that is dead level. The bow means that the slab only sits on the end two brackets, but since they are Centerline brackets rated for 100lbs each and the slab weighs 50 lbs tops, that should be fine.
I was hoping to get some advice from the experts on the following questions:
1. Is my "do nothing" approach reasonable? Posts here seems to suggest that 0.25" of bow over 7' is entirely expected and that even the 0.5" bow that I have is not too much to worry about.
2. Should I add a shims so that the slab also rests on the middle two brackets or just leave it alone?
3. The brackets don't have screw holes, so to stop the slab tipping when someone leans on the edge, I am planning on attaching a 4" mending plates with #8 or #10 screws that sandwich the bracket between the mending plate and the slab. I'll do this with the two end brackets, since they are the ones that make contact with the slab. Since the slab will be able to move relative to the brackets and will only be fixed along its center line, I think I'll be fine for expansion across the grain and any small movement along the grain. Does this sound reasonable? I'm trying to avoid drilling into the 0.5" inch steel bracket to make a slotted hole as I don't have the metal-working gear to do this.
Thank you in advance for any advice.