[Greenbuilding] Insulation fasteners

Thu Nov 15 13:55:13 CST 2012

We used the FastenMaster Headlok screws to go through 1x4 cedar furring
strips, 4" of polyiso rigid foam (2 x 2" layers), 1/2" of Zip System Panels
exterior sheathing, 1" old lap siding.   We used their 8-1/2" screws to go
2" into the studs.

The screws were expensive, but worked great.

Rob

On Thu, Nov 15, 2012 at 11:48 AM, John Straube <jfstraube at gmail.com> wrote:

>  What do I think is incorrect and misleading? For a start
> 1. long screws are structural.
> 2. you cannot screw a long screw into an assembly without torqueing off
> the head
> 3. you cant find #10 screws in long lengths
> 4. fastening is the over riding cost for attaching foam through furring to
> wood frame walls
>
> How does this impede progress?
> A major improvement in durability and energy performance can be achieved
> by applying exterior insulation to wood and steel framed buildings.
> Unfounded or out-of-context statements like 1 thru 4 cause people to not
> attempt this technique. They dont even try.  Once someone builds a few
> houses, often just part of a single one, it becomes clear that 1 to 4 are
> not true.  I have seen this happen repeatedly over the last decade. People
> in workshops, seminars, conferences, and design offices regularily say
> these things (another common one is "a few screws cant hold up "heavy"
> siding like fibre cement).  I have been showing case studies and doing
> demonstrations for more than 10 years to answer these types of questions.
> When people actually get around to trying this, wether architect, code
> official, contractor, trade, or home handyman, those objections go away.
> Because they are not true. This is the reason I care so much about the
> topic and why it frustrates me.
>
> This thread was not about EIFS.  It was about Bill Allens question on
> fastening foam and furring to walls.  I mention EIFS and roofing since they
> make and use the fasteners required for attach foam. You dont need washers
> when attaching wood furring through foam.  So dont buy the washer.  Hence
> the prices I quoted are valid. You can try and use adhesives for attaching
> siding to a wall, but I dont think it will work, and wont comment further
> till I try it.
>
> Fewer large and more expensive screws at wider spacings can work to hold
> up the cladding, but the suction wind loads tend to cause the furring strip
> (1x3 and 1x4) to fail in bending between widely spaced screws.  You dont
> need a big screw for spacings  of 2 to 3 square feet of area.  Once you go
> beyond that, you get to vertical spacings of 24 to 36" (and yes 1/4" and
> 5/16" dia screws are needed at that spacing) but then the suction loads of
> the cladding cause 1x furring to fail in bending.  So you would have to use
> 2x furring.  Technically fine (36"x24" spacings of 5/16" screws will work)
> but the cost and resource use of 2x3 or 2x4 furring tends to argue against
> it.
>
> Again, I want to emphasize, furring strips through 2, 3, 4" and more of
> foam has been done in dozens of states and many provinces on hundreds of
> projects (that I know about, likely much much more) and this is no more,
> often less, challenging than figuring out how to attach drywall to
> framing.  The ONLY thing that is difficult to do is find the screws at a
> retail level.  It regularly is challenging for people who come across the
> idea for the first time to understand and believe the idea.
>
>
>  Dr John Straube, P.Eng.
> www.BuildingScience.com
>
>  On 12-11-15 1:04 PM, John Salmen wrote:
>
>  What is incorrect and false and impedes what kind of progress?****
>
> ** **
>
> I am not talking about mechanically fastening foam we are talking about
> fastening wood against foam through to framing. EIFS screws and washers
> like dekfast and windlock are great for attaching foam (if you need to) but
> you need the washer so still about .35 per screw *and *washer – and it is
> usually minimum1 screw per square foot for eifs. That is the equivalent
> cost of 2” of eps (I pay about .18 per board foot for eps). I am not sure
> what is progressive about thousands of screws and plastic washers - I
> prefer foam adhesives****
>
> ** **
>
> So for mechanically fastening battens or wood components against foam ONE
> large head structural screw at framing intervals at a cost of .30 per screw
> is I think a pretty responsible approach  (don’t buy them at home despot).
> And yes screw heads snapping or screws bending is a common problem when
> embedding a long low strength metal screw 1-1/2” into spf framing. And I am
> not sure why there would excuses if there wasn’t a perceived problem.****
> ****
>
> ** **
>
> ** **
>
> ** **
>
> *From:* John Straube [mailto:jfstraube at gmail.com <jfstraube at gmail.com>]
> *Sent:* November-15-12 6:36 AM
> *To:* John Salmen
> *Cc:* george at houseisasystem.com; 'Green Building'
> *Subject:* Re: [Greenbuilding] Insulation fasteners****
>
>  ** **
>
> John, much of what you say is not correct. This bothers me because I
> routinely hear these false claims made, and this incorrect information
> impedes progress in making good energy efficient buildings (something I
> know you care about).
> *You can get long screws that are not "structural screws".*  I know,
> because we and many others installing thick layers of foam insulation and
> have been doing this for years. There must be a few dozen case studies
> alone on our website.
> Yes, long structural screws are what you find at Home Depot, but these
> expensive and problematic in a number of ways.
> It is quite possible to get #10 or #12 screws in lengths of 6" and up.
> #10 is typically only available to about 6" length, and then #12 to about
> 12 or 14" long, and then you are up to #14 / 1/4" dia for lengths up to 20"
> or so. We regularily find that a #12x6" can be cheaper than a #10x6" and
> thus use them, but #10 is what we have always tested in the lab because
> they are the smallest available and hence the most flexible with the lowest
> pullout loads.  Their heads DO NOT torque off when used to attach foam.
> They are NOT intended for screwing through solid wood but through
> insulation, which is why they work perfectly well.  Millions of 6" long or
> longer screws are installed every year through foam in the commercial
> low-slope roofing and EIFS industry (see for example Wind-lok for #10x6"
> long).  This is the first stop if you are looking for long thin screws that
> have corrosion resistance, are easy to install and affordable.   These
> products in these building niches all have a long track record of being
> installed  by the thousands without problems of torquing off heads, driver
> slippage, bending, or whatever other excuses I have heard. They have been
> designed for embedding about 1 to 1.5" in wood after screwing through 4-12"
> of roof  or EIFS insulation. What is not easy for individuals and small
> contractors is finding these screws because they are typically carried by
> larger supply houses and commercial sales outlets.  If more people start
> super insulating their houses, I am pretty sure the fastener industry will
> respond by marketing their roof screws as wall screws and the problem will
> go away.
>
> The HeadLok screws are great for many structural applications, but I think
> these are used for attaching foam and furring only because they are
> available at retail outlets. There are quite nice, but are usually twice as
> expensive as the alternatives (40 cents each and up), and often three times
> the cost retail (eg we get supply house prices of 12 cents on a #10x6" and
> the contractor tells us that HeadLok or GRK cost $150 for a 250 pack).
>
> *The screws are also NOT the most expensive part of the assembly.*  Not
> even close.
> If you purchase relatively heavy 6" long screws from, say, here
> http://www.bestmaterials.com/detail.aspx?ID=9221
> They cost maybe 20 cents each (these are #12-14 screws)   Not the cheapest
> source but not bad.  Often available for 15 cents.  If you use one screw
> every 12" vertically and 24" horizontally (pretty conservative), that is 1
> screw per 2 square feet or about 10 cents/square foot at 20 cents each.
> When labour is added, the screw might be 3 times as expensive (30 cents
> /square foot).
> 4" of polyiso will cost something in the order of $2 to $2.50 per square
> foot, making the screw less than 5% of the cost of materials for the
> exterior insulation (adding the cost of furring strips changes little). 4"
> of EPS will be about $1.50.  With labour, the screw is still around 10% or
> less.
>
> ****
>
> Dr John Straube, P.Eng.
> www.BuildingScience.com****
>
> On 12-11-14 11:10 PM, John Salmen wrote:****
>
> When you get into long screws they are structural screws - equivalent to a****
>
> 3/8" bolt (actually better). For sure they are overkill but that is where****
>
> eng. crosses practicality. When you increase length on anything the design****
>
> requirements for actually getting the screw into the material override the****
>
> design criteria for loading. The reason being that you cannot screw a long****
>
> softmetal screw into an assembly without torqueing off the head. - I don't****
>
> even think you can even find a #10 standard soft metal screw in long lengths****
>
> anymore - I remember putting an order in from one manuf. a decade ago and****
>
> half the screws were thrown away from having heads torqued off. 1/4" and****
>
> 3/8" lag bolts would also self destruct far too often in application to make****
>
> them practical for a load that an 1/8" of metal would carry. We are talking****
>
> about crews that have to install a lot of bolts/screws in a day and wasting****
>
> their time with defective material is an overriding consideration.****
>
> ** **
>
> Headlok screws that I mentioned will cost about .30 per for 6" and about .50****
>
> per for 8" and each screw will do what is supposed to do. They drive in****
>
> quickly and perfectly each time. They have a large wafer head equivalent to****
>
> a washer so one screw generally takes the place of at least 2 screws in****
>
> design. ****
>
> ** **
>
> Fastening is the overriding cost in assemblies at this point and it is split****
>
> between the cost of the fastener and the time taken to fasten. That is why****
>
> most buildings are being put together with adhesives.****
>
> ** **
>
>   ****
>
> ** **
>
> -----Original Message-----****
>
> From: Greenbuilding [mailto:greenbuilding-bounces at lists.bioenergylists.org <greenbuilding-bounces at lists.bioenergylists.org>]****
>
> On Behalf Of George J. Nesbitt****
>
> Sent: November-14-12 6:57 PM****
>
> To: jfstraube at gmail.com; Green Building****
>
> Subject: Re: [Greenbuilding] Insulation fasteners****
>
> ** **
>
> I'm about to screw through 4-1/2" of polyiso, I can only find 6" screws****
>
> affordably ($13/100ea), longer screws are $1ea. Sources & prices for 6"+****
>
> #10 screws?****
>
> ** **
>
> On 11/14/2012 7:53 AM, John Straube wrote:****
>
>  We have tested up to 8" of foam (EPS, XPS is stronger) with #10 screws and****
>
>  furring strips. Works fine with siding ( safety factor of more than 10).****
>
>  3/8" lags is crazy: never need it. The foam provides a lot of the****
>
>  strength.****
>
>  Check our buildingscience.com website or my book for more detail on how****
>
>  this works.****
>
>  ** **
>
> Sent wirelessly from my BlackBerry device on the Bell network.****
>
> ** **
>
> -----Original Message-----****
>
> From: Clarke Olsen <colsen at fairpoint.net> <colsen at fairpoint.net>****
>
> Sender: "Greenbuilding" ****
>
> <greenbuilding-bounces at lists.bioenergylists.org> <greenbuilding-bounces at lists.bioenergylists.org>****
>
> Date: Wed, 14 Nov 2012 09:50:23****
>
> To: Green Building<greenbuilding at lists.bioenergylists.org> <greenbuilding at lists.bioenergylists.org>****
>
> Reply-To: Green Building <greenbuilding at lists.bioenergylists.org> <greenbuilding at lists.bioenergylists.org>****
>
> Subject: Re: [Greenbuilding] Insulation fasteners****
>
> ** **
>
> _______________________________________________****
>
> Greenbuilding mailing list****
>
> to Send a Message to the list, use the email address ****
>
> Greenbuilding at bioenergylists.org****
>
> ** **
>
> to UNSUBSCRIBE or Change your List Settings use the web page ****
>
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.b****
>
> ioenergylists.org _______________________________________________****
>
> Greenbuilding mailing list****
>
> to Send a Message to the list, use the email address ****
>
> Greenbuilding at bioenergylists.org****
>
> ** **
>
> to UNSUBSCRIBE or Change your List Settings use the web page ****
>
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.b****
>
> ioenergylists.org****
>
> ** **
>
>  ** **
>
> ** **
>
> --****
>
> George J. Nesbitt, Environmental Design / Build, Building Performance****
>
> Contractor HERS I Verifier & HERS II Rater, GreenPoint Rater new & existing****
>
> SF & MF, CABEC CEPE (Certified Energy Plans Examiner), Certified Passive****
>
> House Consultant, BPI Multifamily Analyst, www.houseisasystem.com, (510)****
>
> 655-8532 office, (510) 599-5708 mobile****
>
> ** **
>
> _______________________________________________****
>
> Greenbuilding mailing list****
>
> to Send a Message to the list, use the email address****
>
> Greenbuilding at bioenergylists.org****
>
> ** **
>
> to UNSUBSCRIBE or Change your List Settings use the web page****
>
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioener****
>
> gylists.org****
>
> ** **
>
> ** **
>
>  ** **
>
>
>
> _______________________________________________
> Greenbuilding mailing list
> to Send a Message to the list, use the email address
> Greenbuilding at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org
>

-- 
"I still find each day too short for all the thoughts I want to think, all
the walks I want to take, all the books I want to read, and all the friends
I want to see." — John Burroughs (1837-1921) American naturalist, writer
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/greenbuilding_lists.bioenergylists.org/attachments/20121115/b548733a/attachment.html>