How to Fit a Zipbolt

You will need to use a Zipbolt when attaching your main stair string to your landing string. If you are unsure how to do this, read the following step by step guide.

Mark from the centre to the edge of each hole

Find the centre of the 25mm holes at the top end of the already assembled string and draw a line straight to the edge of the string.

Mark down the edge

Continue the line straight down across the outer edge of the string.

Mark halfway down

Drop a square on the edge of the string and mark a cross line 16mm down (1/2 the width of the 32mm thickness of the string).

Drill through

Using a 12mm spade drill, drill through the centre of the cross line until breaking through to the 25mm hole.

Line up the stair and landing strings

Next locate the landing string. Line up the trenchings and whilst keeping the landing string flush to the already assembled string follow the centre line from the 25mm hole over to the landing string.

Mark the landing string

As previously done on the assembled string, using a square, follow the line down the edge of the landing string and mark a cross line 16mm down.

Drill the landing string

Using a 6mm diameter drill for pine or for oak strings an 8mm diameter drill, drill a hole down the centre line marked on the landing string to a minimum depth of 60mm to receive the bolt.

Insert the bolts

Once the holes are drilled then insert the bolts using a 7mm hex bit. Drill in the 1/4" threaded end of the bolt to just above the back shoulder of the thread.