H Clip On Roof Sheathing Over Skip Decking

Simpson strong tie panel sheathing clips are used to brace unsupported sheathing edges and provide a 1 8 gap to address shrinkage and expansion of roof sheathing.

H clip on roof sheathing over skip decking.

We recently installed a zip system roof over roof trusses spaced 24 inches on center. The lumberyard told us to install h clips as for conventional sheathing but after taping over all the seams between panels we found that water leaked through the tape at almost every clip. Some older h clips do not provide a built in gap. The house has 24 oc trusses with 3 8 plywood and h clips.

H clips provide additional stiffness between bearing points for the unsupported edges of wood panel plywood or osb roof sheathing along with the necessary 1 8 gap for expansion as shown below illustrated on a bag of simpson h clips. The crew stripped the roof and nailed a second layer of 1 2 plywood over top of the 3 8 existing layer. Help prevent sheathing warping our clips leave a precise 1 8 gap created from a full width spacer bar without this full gap sheathing can expand under moist conditions and you can end up with the sheathing. Some other clips can poke holes in it and cause leaks.

When a cedar shake roof needs replacing the shakes should be removed and the skip sheathing sheeted over with solid plywood. Help prevent roof leaks many tile roofs have a polymer underlayment our clips work very well with the polymer underlayment. When you think of a modern plywood roof deck you re not imagining gaps between the sheets of plywood. I don t know how they handled the h clips but we never went over the original sheathing we stripped it and started with new plywood.

Not always required but a good idea. Osb or plywood over skip sheathing makes for a much stiffer roof deck resists problems with expansion better and obviously doesn t require all the hassle of removing it. Later i heard that the h clips weren t needed in the first place. A strong resilient roof is a home s first line of defense when the roof deck is exposed to weather.