Get a grip
- Oct 4, 2016
- 2 min read
The I-beams and glulam beams span the width of the building and sit on two purlins which run along its length on either side. These purlins are attached to the inner flanges of the rib beams. Later braggers (wooden corbels) will be secured below the purlin to provide more strength.
The beams that are adjacent to rib beams extend through the wall to the outer rib beam flange and are bolted to both the inner and outer flanges to keep them in place. Two bolts are used to connect to each flange. To bolt them a 12mm hole is bored through the beam and flange. Through this hole a steel rod is inserted and is secured on either side with a washer and a nut. In some places the bolt passes through two beams (one either side of the rib) as well as the rib beam.
On the big glulam beams dog tooth timber connectors have been used in place of washers. These connectors are commonly used in between two pieces of timber that are being bolted together to give a good grip. Here they ensure a the bolt securely grips the beam.
On each side of the stair void are 180cm beams created by gluing and screwing 2 no 90cm glulam beams together. Sourcing the structural Paslode screws was nigh on impossible. Local builders' merchants have structural screws but not in the size we required. I don't know how the pros manage - perhaps they have direct arrangements with the manufacturers. Eventually I found someone in Glasgow selling them on eBay. The boys were impressed with them. Them be REALLY GOOD SCREWS.
Bolting these beams is proving to be tough going. Drilling through the ply rib flange the drill bit frequently hits nails within the ply. Even a metal drill bit struggles as it's not going through solid metal but rather bounces off the surface of a nail.
All this metal work needs to be covered with anti-corrosion tape. Woman's work no doubt. Sigh!
No dogs were harmed in the making of this post.
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