Replies

1. 
   duster1 | Sep 01, 2005 03:26am | #1

   Check with an engineer- but I have seen holes drilled through the block
   wall to go through metal plate the length of the deck. You then
   sandwich the block between the outside ledger board and flashing and the
   metal plate inside (with thru bolts and locknuts)
   But first, describe the house framing on top the block wall; got a rim
   joist or not? Maybe a little more detail on the project.

1. 
   pahammer | Sep 01, 2005 10:18pm | #8

   i would like to build it independenly but the sewer line run along the house next to the wall.  the whole first floor is concrete block so a there is no rim joist.  there is an existing covered porch over where this deck will be built.  also the inside of the block wall is finished room so through bolts are out of the question.  thanks for all the ideas.

1. 
   PeteDraganic | Sep 01, 2005 10:28pm | #9

   You can set the posts 2' in from the outside wall of the house (or more) depending on the joist or beam size/span. 

   http://www.peteforgovernor.com

2. 
   BuiltByMac | Sep 02, 2005 06:10am | #10

   I second Pete on pulling the posts/beams away from the block wall and cantilevering the joists up to the block wall. 2x8 joists will cantilever 18" - 24" over the beam as long as the total length of the joist is longer than 6'. Keep this deck freestanding.Mac

2. 
   Dinosaur | Sep 01, 2005 03:27am | #2

   Do not repeat 'not' use Tapcons. They are too brittle and will snap sooner or later. More likely sooner....

   You have a choice of drilling between two courses of block and using lead anchors and lag screws (5/16"x3");  or of drilling into the cavities in the block and using toggle bolts. Don't try to use short expanding anchors of any type in the 'skin' of the block; they'll crack it when you crank down on the bolt or lag screw.

    

    

   Dinosaur

   A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...

   

   But it is not this day.

3. 
   MikeCallahan | Sep 01, 2005 04:15am | #3

   Drill all the way through the block wall and use 3/4" machine bolts at 24" centers staggered with large square washers. Do not use lags or lead shields. If you have snow loads or impact loads then consult an engineer.

   Mike Callahan, Lake Tahoe, Ca.
4. 
   Matt | Sep 01, 2005 04:20am | #4

   If it is a ground level, why attach to the wall at all?  Unless you just want some superficial attachment to keep a gap from forming between the house and the deck.   If that is the case, just about kind of screw/anchor intended for the purpose will work.  Drill into the mortar joints - either the horizontal or the vertical ones. 

   Either that, or maybe you are in earthquake country?

5. 
   RW | Sep 01, 2005 06:59am | #5

   One solution which came up during a church remodel when we had to attach the floor of the new pastor's office to a hollow core block wall (and thank God for the engineer there) was using an epoxy "umbrella" anchor. The way it works, you drill the hole, stick the umbrella thing in, the back expands not unlike a molly, or something in your girlfriends drink, you pump it full of epoxy and set your allthread in it. Cure time, then bolt on the ledger. Worked pretty slick.

   "If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man." - Mark Twain

6. 
   tmaxxx | Sep 01, 2005 04:45pm | #6

   i use this type of stuff all the time.  we use it for pretty large forces.  i think if you read the specs it will be more than enough for you.

   http://www.us.hilti.com/holus/modules/prcat/prca_navigation.jsp?OID=-12139

    

   Tmaxxx

   Urban Workshop Ltd

   Vancouver B.C.

   cheers.  Ill buy.

1. 
   PeteDraganic | Sep 01, 2005 07:03pm | #7

   The best way to attach a ground level deck is to not attach it.

   unless there is a great reason for it, I always build my decks as independent structures.  I never attach them to the house and do not recommend that anyone else should either.

   http://www.peteforgovernor.com