Sill Anchors 1

[Deutero]

Is there was a requirement, in IBC, stating that when fastening preservative treated wood sills to concrete foundation, the anchors must be of corrosion-resistant material such as galvanizing or stainless? I thought there was and I cannot find it.

Thank you...

 

[SlideRuleEra]

Yes, in IBC 2003 it is Paragraph 2304.9.5 which reads "Fasteners for preservative-treated and fire-retardant-treated wood shall be of hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze or copper. Fastenings for wood foundations shall be as required in AF&PA Technical Report No. 7."

http://www.SlideRuleEra.net

 

[Deutero]

Thank you SlideRuleEra for your reply. The reason I ask, is because for several years, the contractor I work most closely with, has been wanting my firm to conform to the other architect and engineering firms that they work with. Those other firms have been specifying 1/2" anchors (w/o galvanizing or stainless) based on the 2003 International Residential Code.

Through research, I have spoken to the key structural code reviewers for the state of Wisconsin, who, though they may agree that the 1/2" anchors may be effective, the IBC simply states as stated in 2304.9.5.

I'd love to join the crowd, but code will not permit. Does anyone know of any way, that I might be over-looking, that might permit me to specify 1/2" anchors? What does AF&PA Technical Report No. 7 say?

 

[DonPhillips]

Here is what the 2003 IRC states:
R319.3 Fasteners. Fasteners for pressure preservative and
fire-retardant-treated wood shall be of hot-dipped galvanized
steel, stainless steel, silicon bronze or copper.
Exception: One-half-inch (12.7 mm) diameter or greater
steel bolts.

Depending on your state code, if applicable, the IRC covers 1 and 2 family dwellings and you can use it for 3+ family dwellings as a design option.

In Ohio, the IRC covers 1, 2 and 3 family and 4+ family in use group R-3 and the codes are mostly based on the 2003 I-codes.



Don Phillips

http://worthingtonengineering.com

 

[Deutero]

I forgot to add. My firm does not do residential. Is there anything in any code, regulation, ordinance, etc, that would allow 1/2", non-corrosive finished, sill anchors, for fastening preservative treated wood to concrete foundations, for commercial structures?

Thank you...

 

[FSS]

Look at Simpson Strong-Tie's website. They have a great technical bulletin describing treated wood and the corrosion effects on fasteners. A lot has to do with exactly what treatment was used. If ACQ, you better have some corrosion protection for your fasteners.

Corrosion does not care what the code says or does not say...

 

[RARWOOD]

I think the IRC exception for 1/2" diameter bolts is based on the belief: that the amount of time required to corrode the 1/2" bolt to the point that it now longer provides the strength required for the application, provides an adequate factor of safety for residental applications.

I would not recommend using non-corrosive resistent fasteners for attachment to ACQ treated wood. Based on some of the stories I've heard I would not be surprised that at some time in the future the 1/2" bolt exception is eliminated.

 

[DonPhillips]

Another options
1) do not used treated wood. If the sill is high enough above grade, treated wood may not be required. Or use another method of foundation achorage.
2) use a borate treated wood for the sill. I understand this is not corrosive to steel fasteners but is not rated for exterior exposure. Should be OK for a foundatio anchor.
3) use a wood that is naturally resistant to decay and termites like cedars and other woods listed in the code.
4) use a stainless steel anchor.

Don Phillips

http://worthingtonengineering.com

 

[Ron]

FSS..."Corrosion does not care what the code says or does not say..."....same might be said of some contractors!<g>

DonPhillips...if the wood is in contact with concrete, it should be treated, without regard to its other exposure. The perimeter sill is an exterior condition...I wouldn't use borate treated wood there.

 

[DonPhillips]

Just saying the building code allows the sill to be untreated but I disagree it is always exterior. It can be detailed to be protected from direct exposure to rain.

Don Phillips

http://worthingtonengineering.com

 

[unclesyd]

Here is a lot of the information available. Also click on the list of vendor components that are recommended for ACQ.

http://www.ufpi.com/product/ptlumber/fasteners.htm

Two local fastener suppliers are telling me that the are getting complaints of coated fasteners having problems in outdoor applications especially near the water. Also galvanized fasteners are given problems on docks and piers. The Galvanize problem might stem from some of the lower quality fasteners in the market. Good quality HDG galvanized fasteners are expensive, probably twice the cost merchant grade.
For residential including multifamily dwellings CS is the still the predominant anchor bolt material.