Fastening A Ledger To Hollow Block

HammeremmaH

I know this question has been asked before, but the answer was insufficient for my purposes.

Throughout my career I have used sleeve anchors(formerly lead shield/wedge anchors) to attach deck ledgers to both solid foundation walls, and concrete block foundation walls (never to brick veneer, so don't even bother bringing it up).

Now I have come across information that this may not be proper when dealing with hollow block foundations.

Redhead's Dynabolts state they are usable in hollow block (see link below), but never mention anything on their applications section in the vein of attaching ledgers, and call them applicable in "medium-duty" applications. However they do offer these performance tables (the last chart, see link below). Problem is, I'm not sure how to figure how much strength I would need to even be able to use the tables to determine if they're any good.

I guess my questions/concerns are this: what methods should be used to attach to hollow block and are sleeve anchors acceptable?

Please don't suggest to "just go freestanding" b/c you should know that's not always an option. Also, I know adhesive anchors are an option, but they are VERY expensive and not always available. Hell, and while we're at it, are sleeve anchors acceptable in solid foundation walls? Code here says they're good, but that whole "medium-duty" thing is making me rethink everything.

Thanks to all.

Hmmm ..Apparently, I'm not allowed to post URLs until I've made 15 posts, obviously to stop phishing and bots. But since I'm neither I think the mods will let me get around that. Just add 3 Ws and a dot to the beginning of the links below.

itwredhead.com/dynabolt_prod01.asp
itwredhead.com/dynabolt_perf01.asp

dakzaag

Best solution would be to fill the cores with grout if that is an option. Realize that block has very high compressive strength, but lateral strength is marginal.

Personally I would only bolt all the way through if the block are not filled and then I would still prefer to get grout in the cores if at all possible.

Do you have a detail in the prints, or is this self engineered?

I think your lead anchor sleeves in solid concrete should be fine if they are sized properly and allow for minimum clearances. Engineer Stamp is your friend, but I realize this is not always possible.

Hope this helps, not a deck builder, but will be laying block all day tomorrow.

__________________
D K & Sons
The maintenance schedule for brick
1. Stand back and say "man that looks nice!"
2. Repeat as often as needed.

macatawacab

If I am understanding your question, you are attaching a deck ledger board (2x10) to a CMU wall?

IMO, If all you are doing is running 2x10, 16oc, plus deck boards, there is not much load. Sleeve anchors are way better than lead. There are several factors to consider and sleeve anchors (Redheads as an example) excell at these; shear and withdrawal. A 1/2" bolt will meet your requirements. Spacing is the next issue. This will take research.

I agree that an engineer is your friend. Get a signed drawing showing size and spacing for one typical installation and keep that with you for all your future jobs.

HammeremmaH

Thanks for the replies guys.

Correct, I am speaking of a CMU wall.

If I were to fill the voids what sort of grout would be appropriate? And how long would I have to allow it to cure?

Other opinions and replies are welcome.

Danno6102

My engineer recommended the Hilti HLC Sleeve Anchor. I haven't used them yet. It was just one of those things that came up in casual conversation & he spec'd it up for me. I don't think they make galvanized so the SS would be what you'd need to use. 3/8" is the largest they have in Stainless. 890# in shear & 470# in tension. I'd still install some bracing on the outer beam to prevent the deck from pulling away from the house & pulling the block over.

Tom M

I've had success using the appropriate Hilti Sleeve and epoxy system. It expands to increase its bearing surface in shear. There is a weight limit so spacing has to handle the load. Some homework is needed for any town to approve plans.

RobertCDF

Check these out we dont have block foundations here but I have used these in place of a toggle bolt for much lighter stuff.
http://www.toggler.com/products_hwh.html
They really are nice the way they work over conventional toggle bolts.

__________________
Robert Shaw
Colorado Springs Custom Decks
Colorado Custom Decks
Custom Composite Decks