Need help with H-Clip Support

In Wisconsin, building codes do not require the installation of H-Clips between the 4 x 8 roof decking. There is a builder that builds homes to “Code” and we all know that may not be the best way to build a home. Most good builders I’ve talked to wished that decking manufacturer’s would make 7/16" OSB decking 1/2" shorter on the length because it would save alot of time vs trimming the ends.

I’m looking for solid support on this matter. Most of the responses I’ve received from others in the building industry says they should be used but if the roofing contractor properly spaces the decking, everything is OK.


I, Joe subcontractor, understand that Joe shingle manufacturer or Joe decking manufacturer requires the use of H-clips to be installed in order for our, Joe shingle manufacturer’s warranty to be enforcible. The use of H-clips guarantees the minimum spacing of 1/8" is maintained and will allow the roof deck to normally expand and contract with normal environmental conditions. Joe subcontractor understands , this requirement and if Joe subcontractor chooses to use alternative installation methods that are found to be below the manufacturer’s recommendations, Joe subcontrator assumes full liability and responsibility to assume Joe shingle manufacturer’s warranty on said product.

Being honest and up-front IMHO is the best thing we can do for all parties. If somebuilders/contractors choose differently, then let’s get a couple of signatures up front.

I’m really hoping for some solid help with this. and no offense intended for the Joe’s in this world.

Are you sure the OSB is not allready sized for spaceing?

Are they BUTTING it up tight on the walls also?

Why would anyone use 7/16 OSB on a roof, we always use either 5/8 fir or 5/8 Avantech and the only time I use H clips is on trusses 24" O.C.

Not sure what your standards are but that’s ours.

Someone needs to tell them in the KC Metro. They send out the same for walls and roofs. Or so it seems. Maybe the carpenters can not read! And the city inspectors do not care! And the homeowners do not know!

CHACHING money in the bank for the builders!

The OSB roof deck were tight along the axis. There was no way to inspect the spacing over the trusses

Trusses are usually spaced 24" OC and the typical decking is 7/16 OSB. I did get an e-mail reply from Certainteed that H-Clips are not required for their warranty to be enforceable.

Many, if not most, jurisdictions do not do roof nailing inspections on residential construction anymore. Clips are an improved method but not required by model code.

So what is the client’s recourse? I couldn’t get an image to upload with the detail necessary to see the entire roof but hopefully you can see the problem with these pictures.



It’s a good idea to space them, but there’ve been a million installed butted tight. If they get wet, they’ll start to bow. 7/16" gets used many, many places for walls and roof. Most of the bowing I’ve seen have been problems from butting them tight end to end (which you couldn’t see from below anyway, unless they really screwed up). Butting them tight along their length doesn’t seem to be a problem as often, but doesn’t mean it won’t be.

Recourse is to keep the roof dry and hope for the best or back out of the deal. If I liked a home, I wouldn’t back out because of this. Buyers do need to know it’s a potential problem.

I agree with Kenton. The governing body for plywood installation, APA, recommends a 1/8" gap but it is more the exception than the norm from what I’ve seen. Here is a blurb from a FEMA document on roof sheathing (note that it DOES mention your idea comment about trimming the panels slightly short but only on plywood marked as such:

“Install sheathing panels according to the recommendations of the Engineered Wood Association (APA). Use panels no smaller than 4 feet long. Blocking of unsupported edges may be required near gables, ridges, and eaves (follow design drawings). Unless otherwise indicated by the panel manufacturer, leave a 1/8-inch gap (about the width of a 16d common nail) between panel edges to allow for expansion. (Structural sheathing is typically cut slightly short of 48 inches by 96 inches to allow for this expansion gap – look for a label that says “Sized for Spacing.”) This gap prevents buckling of panels due to moisture and thermal effects, a common problem.”

You can find this document at

Hope that helps…a little.

The only time we use clips is on a 24 OC roof, otherwise we butt them up tight, no problems here.

PS. I also never go less than 5/8 on a roof and mainly use square edge Advantech, very stable product with a 50 year warranty.

I agree with Randy. Some times when they do a nailing inspection they look for the gap between the panels. I imagine thats another reason they invented h clips.

You’ll never guess what happened over the weekend. I recieved a call from the owner of joe construction company thanking me for all of the good work I’ve done for my clients that used his Real Estate Co.

We got into the discussion regarding H-clips and I explained my opinion to him and eliminating any potential concerns a client may have with the home his company is building for them due to decking not installed to the manufacturer’s recommendations.

He knows that I have a client that is having a home built by his company and he told me that they will be using H-clips on this home because of what I told him and that they will evaluate the process. His thought was the increased material cost (about $50) and the little labor it takes to install them may be well worth any potential complaints from HIS Clients

Hoooray for the home buyer!!! :smiley:

This might help: