Expansion Anchor Connection to Concrete Wall
Expansion Anchor Connection to Concrete Wall
(OP)
I have a wood beam running parallel to a concrete wall. The beam is an edge beam for a new deck design and need to know how to properly design the expansion bolts connecting the beam to the wall. Can someone please offer some help?
Thanks!
Chris
Thanks!
Chris






RE: Expansion Anchor Connection to Concrete Wall
RE: Expansion Anchor Connection to Concrete Wall
John Southard, M.S., P.E.
http://www.pdhlibrary.com
RE: Expansion Anchor Connection to Concrete Wall
Are you a contractor or an engineer? Just curious.
As steellion pointed out, wood connections are a specialty of Simpson StrongTie, so an appropriate hanger or connector can be selected from their catalog based on your loading. The connector can then be fastened to the masonry with a variety of fasteners, from expansion anchors to TapCon-style fasteners.
Ron
RE: Expansion Anchor Connection to Concrete Wall
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Expansion Anchor Connection to Concrete Wall
DaveAtkins
RE: Expansion Anchor Connection to Concrete Wall
No, I am not an actual Engineer or Contractor. I am working on an Architecture degree but really enjoy the structural side of things. Unfortunately, the college I go to does not offer more than just a basic structural theory class. I have taken it upon myself to go beyond what they taught us in class by reading books and asking questions here.
RE: Expansion Anchor Connection to Concrete Wall
If the application would put the expansion anchors very close to a concrete edge, I would resommend a chemical anchor to avoid spalling the concrete.
If that is not the case here, then no worries.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Expansion Anchor Connection to Concrete Wall
One of the posters above mentioned a masonry wall. If the wall is indeed masonry and it is hollow be very careful. There are few anchors suited to hollow CMU construction and those that are have small allowable loads.
RE: Expansion Anchor Connection to Concrete Wall
If this is an exterior application, which I presume it is, I would recommend using spacers (say 1/2" x 3" PT plywood strip vertically) at your bolts to provide an air space between the concrete and the wood. Helps to minimize the trapped moisture that will ultimately rot the ledger.
Ralph
Structures Consulting
Northeast USA
RE: Expansion Anchor Connection to Concrete Wall
Wow, this whole thread is 5-star suggestions, incl. this one. Kudos to all.
Hopefully not a hijack, but a corollary: in my sub-tropical zone (Miami), the PT wood spacers would indeed extend the life of the ledger, but the spacers themselves would succumb, in an unacceptably short time, and probably even start conducting moisture into the ledger. Is there an approved spacer made of PVC/polymer, masonry, or other impervious material that can do the job?
Thanks in advance.
RE: Expansion Anchor Connection to Concrete Wall
Ledgers and other wood/timber applications in contact with concrete or masonry should be pressure treated with an appropriate level of preservative for the application.
RE: Expansion Anchor Connection to Concrete Wall
RE: Expansion Anchor Connection to Concrete Wall
One thing I forgot to point out is that when you use spacers/shims, you can induce bending in the fasteners so that has to be checked. If less than 1/4", usually not an issue.
RE: Expansion Anchor Connection to Concrete Wall
Coastal S. FL is the most aggressive (in terms of CORROSION) environment in CONUS, i.e. combo of high temps, high humidity, and salt spray. Exposed galvanized doesn't do well; neither do most stainless alloys for that matter.
For the ledger app of this thread, the spacer needs to be part of the protective "sheath" for the anchor bolt, along with quality caulk, or, increasingly, anchoring epoxy (e.g. Simpson Strong-Tie ET/SET).
RE: Expansion Anchor Connection to Concrete Wall
RE: Expansion Anchor Connection to Concrete Wall
(run-on sentence here - sorry)
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Expansion Anchor Connection to Concrete Wall
My advice, from the big picture - change the direction of your deck framing members. Instead of a ledger along the concrete wall, support the main carrying beams at the concrete wall - simple connection, many commercially produced framing connections available. Run the joists parallel with the concrete wall, keeping the first joist 6" or so from the concrete. Cantilever the decking material to the wall, but hold the ends back enough to avoid debris & moisture accumulation along the wall.
Did this on a deck I replaced many years ago. The original was built with a ledger and joist perpendicular on a wood-framed wall. I thought it was going to be a simple deck replacement until I removed the ledger. Water had worked its way down between the ledger and the wall due to accumulated debris. Carpenter ants had found it to be a perfect environment - the damage was extensive.
Ralph
Structures Consulting
Northeast USA