# Sheathing H-clips - When to use?



## SteelToes (Oct 5, 2010)

*plywood clips*

Clips are designed to be placed in between two rafters to minimize the span, in other words they are meant to almost serve as an additional rafter.There should be no need for clips with 19/32 OSB @ 24 O.C for standard roof application unless you are working on a flat roof.

See attached span rating table


----------



## tpolk (Nov 7, 2009)

most dont require on 5/8 with 2' span but I always used as its cheap insurance to eliminate warpage in the open span


----------



## SteelToes (Oct 5, 2010)

tpolk said:


> most dont require on 5/8 with 2' span but I always used as its cheap insurance to eliminate warpage in the open span


Agree, it is a good idea to use clips with CDX plywood , no need to be used with OSB in my opinion being that veneers are alternated and virtually there is no warpage.


----------



## masterofall (May 27, 2010)

With 5/8 you dont need H clips. What is th slope? With a low slope deck you can use T&G below a torch on membrane. If it is a 4-12 slope or greater pass on the 5/8 and go 1/2" with H clips to save some money and 1/2 a log from the veneer mill.


----------



## masterofall (May 27, 2010)

Clips are designed to be placed in between two rafters to minimize the span, in other words they are meant to almost serve as an additional rafter.

I hope I'm not stepping on anybodys steel toes but the H-clip does not alter the span it ties the two sheets together mid span and helps to distribute the load.


----------



## SteelToes (Oct 5, 2010)

masterofall said:


> Clips are designed to be placed in between two rafters to minimize the span, in other words they are meant to almost serve as an additional rafter.
> 
> I hope I'm not stepping on anybodys steel toes but the H-clip does not alter the span it ties the two sheets together mid span and helps to distribute the load.


Hey no you are not stepping on my toes  , i was just trying to simplify for the OP so he can picture the placement , you are right clips do not alter the span ( i meant to say minimize the span of the sheathing not the structure).
:thumbsup:


----------



## J S Machine (Oct 6, 2009)

The roof is a 6/12. The only reason I am using 5/8 decking is because I don't want sagging in between the rafters since they are on 2' centers.


----------



## Gary in WA (Mar 11, 2009)

It appears you are in Alabama. No snow loads? I'd use anything to help OSB in case it ever gets wet. 









http://www.strongtie.com/products/connectors/PSCL-PSCA.asp

Gary


----------



## J S Machine (Oct 6, 2009)

It is rare we ever see snow, and it usually isn't enough to amount to anything. 

Anyway, for the price they would be cheap insurance against warpage, so I guess I'll use them.


----------



## Gary in WA (Mar 11, 2009)

They do give you the required 1/8" gap on the edges, just remember to gap the ends breaking on the rafters as well; http://osbguide.tecotested.com/pdfs/en/el812.pdf

Gary


----------



## J S Machine (Oct 6, 2009)

Thanks. I was aware that there needed to be a gap, but didn't even think about the h-clips providing that gap. I'll just go ahead and use them.


----------



## masterofall (May 27, 2010)

J S I'm in Canada with lots of snow and never used more than 1/2" with H-clips on a two foot span. Low slope roofs with torch on or tar and gravel I've gone heaver, up to 3/4 T&G


----------



## Pattyscourage (Sep 16, 2020)

Help! I am building a pole barn with a metal roof. I had plywood put on early spring but didn't have the funds to buy the metal sheets for the roofing so the plywood has gotten a little bleached. Some of the edges are a little warped. I. Planning on nailing the curled edged down and them applying roofing felt over the top before putting the metal sheets down. Is that ok to do. I will go under the plywood and add some 2x4 between the joist so there is extra wood to attach the metal sheets to is that acceptable


----------



## Nik333 (Mar 1, 2015)

Pattyscourage said:


> Help! I am building a pole barn with a metal roof. I had plywood put on early spring but didn't have the funds to buy the metal sheets for the roofing so the plywood has gotten a little bleached. Some of the edges are a little warped. I. Planning on nailing the curled edged down and them applying roofing felt over the top before putting the metal sheets down. Is that ok to do. I will go under the plywood and add some 2x4 between the joist so there is extra wood to attach the metal sheets to is that acceptable



Why don't you start a new thread?:smile:


----------



## wsa (Feb 22, 2021)

SteelToes said:


> *plywood clips*
> 
> Clips are designed to be placed in between two rafters to minimize the span, in other words they are meant to almost serve as an additional rafter.There should be no need for clips with 19/32 OSB @ 24 O.C for standard roof application unless you are working on a flat roof.
> 
> See attached span rating table


 No, they are not an "additional" rafter and serve no primary structural purpose. They act as a spacer to keep plywood from butting with no room for expansion, and act to keep two adjacent pieces of plywood in the same plane which helps for foot traffic during construction, upflift movement over time, which may protect the underlayment.


----------



## Nealtw (Jun 22, 2017)

Pattyscourage said:


> Help! I am building a pole barn with a metal roof. I had plywood put on early spring but didn't have the funds to buy the metal sheets for the roofing so the plywood has gotten a little bleached. Some of the edges are a little warped. I. Planning on nailing the curled edged down and them applying roofing felt over the top before putting the metal sheets down. Is that ok to do. I will go under the plywood and add some 2x4 between the joist so there is extra wood to attach the metal sheets to is that acceptable


It would be easier to strap the roof 24" on center with 1x4, wouldn't it?


----------



## wsa (Feb 22, 2021)

Nealtw said:


> It would be easier to strap the roof 24" on center with 1x4, wouldn't it?


Not sure what you mean, but H clips kind of take the place of solid blocking where every single seam has wood under it. However, it's not necessary for structure as the sheathing is directionally oriented to carry the load to the Rafters. (Just like if you had 1x8's spanning across not fastened to each other at their edges.)


----------



## Nealtw (Jun 22, 2017)

wsa said:


> Not sure what you mean, but H clips kind of take the place of solid blocking where every single seam has wood under it. However, it's not necessary for structure as the sheathing is directionally oriented to carry the load to the Rafters. (Just like if you had 1x8's spanning across not fastened to each other at their edges.)


Your question was about blocks under the sheeting and that what my answer was intended for. 
H clips are required for 24" spacing so any deflection in one sheet transfers to the adjacent sheet so roofing and paper will not rip at the joint. 
Whether you need H clips or not for 5/8" sheeting, the hint would be, they make and sell them for 5/8 sheeting so I would bet they are required. 
Simpson Strong-Tie 50 Pack 5/8" 20 Gauge Galvanized Roof Clips | Home Hardware


----------



## HotRodx10 (Aug 24, 2017)

Nealtw said:


> Whether you need H clips or not for 5/8" sheeting, the hint would be, they make and sell them for 5/8 sheeting so I would bet they are required.


According to the table in response #9, they're only_ required_ for 5/8" OSB with support spacing between 32" and 40". Obviously, adding them would make the sheathing stiffer than without them, at any span.

Of course, even the person asking the the second question 5 months ago, is probably long gone, so we're probably just arguing amongst ourselves at this point.


----------

