screws in joist hangers

[John Dirks Jr]

I know that drywall screws are not suitable for attaching joist hangers on decks.

Are there other types of screws that are suitable, or should joist hangers always be attached with nails?

[Richard Moore]

John, I believe the main concern is shear strength (aside from rust of course). To accomodate the threads, the shank of a screw is much smaller than the hole it fits through, and therefore much weaker. So, without drilling a larger hole in the hanger, I don't see how any common screw would be the equal of the appropriate nail, or allowed. Same thing for those pull-down ladders.

[Jim Katen]

I know that drywall screws are not suitable for attaching joist hangers on decks.

Are there other types of screws that are suitable, or should joist hangers always be attached with nails?

I believe you can use Simpson Strong Drive screws on their joist hangers.

- Jim Katen, Oregon

[Richard Moore]

I know that drywall screws are not suitable for attaching joist hangers on decks.

Are there other types of screws that are suitable, or should joist hangers always be attached with nails?

I believe you can use Simpson Strong Drive screws on their joist hangers.

- Jim Katen, Oregon

Jim, I had to Google those screws. I can't find anywhere where it says they can be a substitute for nails, when nails are called for(?).

The following is an excerpt from the Simpson pocket guide... http://www.strongtie.com/ftp/catalogs/S-INSTALL06-R.pdf

Click to Enlarge

56.72 KB

[Bill Kibbel]

In 2007 Simpson introduced the SDS Screw with Double-Coat Barrier. It's approved for use with many of their connectors.

They're quite easy to identify:

[John Dirks Jr]

John, I believe the main concern is shear strength (aside from rust of course). To accomodate the threads, the shank of a screw is much smaller than the hole it fits through, and therefore much weaker. So, without drilling a larger hole in the hanger, I don't see how any common screw would be the equal of the appropriate nail, or allowed. Same thing for those pull-down ladders.

In any event, this makes sense.

[SWagar]

A good reference is the Simpson Catalog. For each connector they specify what types and sizes of fasteners can be used. I only have the 2006 catalog at my disposal so I don't see any reference to the S3 screws. A Simpson rep has said that they DO NOT allow deck screws or any other screw that will deform the hole. These are engineered connectors and are designed not to have any of their mounting holes deformed in any way. Take a look at page 11 in Richard's post regarding screws instead of nails.

[Darren]

This question was asked on the ASHI website last year. The SDS screw is designed for deck ledger attachments. This is the reply from Simpson:

Hello Darren,

On behalf of Simpson I’d like to thank you for attending the seminars. As far as your question replacing 16d nails or any other size nail with SDS screws would not be advisable. First place the hole size in the connector would not be large enough for an SDS screw. Simpson does not stand behind products that have been modified, i.e. drilling the holes larger to fit SDS screws.

George Wienholz,

Simpson Strong Tie Co., Inc.

Phone: 925.560.9207

[Bill Kibbel]

Only the SD8x1.25 is prohibited for use with any connectors.

"The Simpson Strong-Drive® screw (SDS) is a 1/4" diameter structural wood screw ideal for various connector installations as well as wood-to-wood applications".

Several hangers are packaged with SDS Screws.