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TOHadvice
Attaching deck ledger

My contractor wants to attach the deck ledger for an supported elevated deck to the end grain of floor joists. Every other floor joist used to extend out 4 feet to support a cantilevered walkway. There is blocking between the exposed joists but no rim board/band joist. The new deck will be a maximum of 8 feet wide. The plan is to use GRKfasteners (structural screws) which will be 32" apart, screwed thru the ledger, one directly over the other (not staggered) into the floor joists. Two concerns: I've read that using 1/2" lag screws in end grain is not advised and that lag screw spacing should be 23" apart and staggered one high, one low. Should I be concerned?

jkirk
Re: Attaching deck ledger

the reasoning behind staggering lag bolts high and low is for when fastening them into a rim board, staggering them makes for less stress on one board so that it doesn't via having several bolts close toghether.. though not advised to drive bolts into end grain having them closer together wont cause an issue as each pair of bolts or screws are going into seperate peices of wood.. it should be fine just as long as the contractor predrills for large screws. driving large bolts into wood without a proper sized pilot holes causees the wood to split and even shear off the bolt if a impact driver or wrench is used.

another major thing that you should make sure of is that the contractor water proofs behind the ledger before its fastened. i use either 12" vycor or blueskin, another option is ice and water shield. once the ledger is on it should be properly flashed with a metal cap flashing.. if aluminum is used it shouldnt come in direct contact with the pressure treated lumber as it will eat the aluminum

TOHadvice
Re: Attaching deck ledger

Thank you for your response

Timothy Miller
Re: Attaching deck ledger

Howdy GRK RSS fasteners do not need predrilling and if you view their videos you see they are designed not to split wood.....
Would use 2 per joist for peace of mind.

jkirk
Re: Attaching deck ledger

didnt know that about grk fasteners. although there a special order item here....

Nick
Re: Attaching deck ledger

The previous comments about your ledger attachment are correct although in your situation i would first add a piece of 1/4" or 3/8" plywood glued and stapled or nailed over the span of the ledger area to tie the blocking and the house floor joist togeather and then add your ice and water shield before legder attachment. your 1/2" lag bolts or GRK RSS structural screws need to be fastened to the solid blocking, (never through the end grain!!) minimum 2 every 16" o.c., they can be staggered although in my exp. it is preferred they be in line to each other.

TOHadvice
Re: Attaching deck ledger

Thanks for the sound advice

jerry69e
Re: Attaching deck ledger

This isnt so simple for atteching to cement block.Ledger installed on my house for enclosure was done with achor bolts driled into cement. Maybe in 1985 it worked but test time it was poor workmanship. Only method to actually be sure the ledger holds tight is to drill threw cement block attaching metal plates both inside cemnt block of home an out side surface of ledger bolts going threw the block.Hard to go back in time fix errors past especaily when earth quake pulled ledger off house.Luckly this enclosure is still standing 7 feet in air. Mainly because its in spot supported by sides or u shape part of cement house. I had professioninal look at this an this what she came up with. Drill the ledger every 24 inches an install threaded rod threw the block. Using threaded rod 12 feet long can attach the ledager to block an facing support beam of out side of enclsorer. This will prepare for sounds construction giving enclosure once all supports are in place an new front beam is install front encloser.Reinforcing encloser will set ground work for new 32/38 foot deck /carport in front of enloser. This carport will have a deck on top with rubber membrane under floating deck.Super structure will have sway/shear supporting 6/6 post. Building post in doubles an attaching them to one another it will give deck support corners will have three post.This is huge project because of extensive work in building foundation an new driveway. But then rome wasnt built in day probley take me 2 years to complete

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