Oak butt weight

[ucoulddoit]

Perhaps it's also worth mentioning, that because of the way timber moves as it dries, boxed heart can potentially split in half (or quarters) lengthways.

 

A boxed heart column will almost certainly develop long splits along its length as it dries, but surprisingly, it's more of an aesthetic issue than a concern about strength, unless it split in half along the full length, but I've not heard of that happening. John Boddy's had a method of drilling a largish hole the full length along the pith/centre which apparently reduced the splitting very significantly. I've also heard of a technique where a saw cut is made the full length of a column on the least visible side (e.g. the side against a wall) and this minimises random drying splits developing on the other sides.

 

I realised my comment about a beam/column drying and distorting into a diamond shape if milled away from the heart doesn't apply for those that are quarter sawn.

 

Andrew

[agg221]

I've also heard of a technique where a saw cut is made the full length of a column on the least visible side (e.g. the side against a wall) and this minimises random drying splits developing on the other sides.

 

Andrew

 

Funnily enough I have literally just installed one of these (finished about 15 minutes ago). The beam section is 9" x 9" to line up with the wall and give headroom. The span is 3.3m so it required a steel flitch plate let in to the top.

 

I milled the original beam and immediately cut the slot with a mini-mill, using the narrowest kerf saw I could get my hands on, which turned out to be my neighbour's McCulloch on a 1/4" narrow kerf bar. I offset the cut 6" - 3" so it lines up properly with the joists, which are notched in, and with the upper beam which is 5.5" wide.

 

Shrinkage in trees is always around the ring, meaning that the slot widened, becoming wedge shaped. I have now trued it up to take a 12mm steel plate which will be bolted through, and made a wedge which will drop in to fill the slot.

 

The first picture shows the side and underside - you can see that this is clean without splits. The second picture shows the slot from the top, which will obviously be under the floor.

 

Alec

[Big Beech]

1 M3 of green Oak weighs around 900kg