Shear lashing

The wraps run around both poles lying side by side. Frapping turns between the poles pull these wraps together. Because the wraps are deliberately not fully tight, some play remains so the poles can be spread later.

As you spread them, the poles rotate against each other at the lashing and tension the wraps. The cord goes taut, presses the wood together, and the lashing grips. The further you spread, the greater the tension – up to the point where the poles will not open any further. To extend two poles, on the other hand, you wrap tightly in two places with a generous overlap, because nothing needs to spread there.

Before spreading, the wraps should lie neatly side by side without crossing, and be just loose enough that you can open the poles with a bit of force. The frapping turns sit between the poles, around the wraps. Start and finish are secured with a clove hitch – one on each pole.

After spreading, the lashing should sit firm and the top of the A should no longer twist. If the A opens out completely flat, the wraps were too loose. If it barely opens, they were too tight. Getting it right takes a little practice – expect to retie it the first few times.

The two tension mistakes are the most common: too tight, so the poles cannot be spread, or too loose, so the lashing does not grip when spread. A third, often overlooked mistake has nothing to do with the lashing: legs that are not secured against sliding.

An A-frame is fairly stable in its own plane, but it can easily topple sideways – like a ladder standing on only two points. On slippery or hard ground the legs can slide outwards, the A gets flatter and the load can come down. That is why an A-frame needs side guying and secured feet.

The shear lashing is the basis for A-frames that carry a ridgepole or ridgeline – for example for a tarp when there are no trees at a suitable distance. With two tight lashings, two short poles can also be extended into one long one.

It is not meant for right-angle joints; the square lashing is for that. Load-bearing structures for people should not be built without expert assessment. Life-safety use only after proper training with certified equipment.

Always set up an A-frame so it cannot fall on you while you raise it. Dig the feet in slightly or brace them with stones, and guy it out to both sides before you put the load on.

Do not stand under a load hanging from an A-frame. After wind or rain, check that the feet are still firm and the lashing still holds. Local rules apply to cutting poles.