Deck ledger board

[DarrellE]

I am installing a ledger board for a deck. I am going to attach it with coach bolts to the house brick wall just below pebble dashing. There will not be a problem with load as I have excavated so that the ledger board will sit on top of the concrete foundation. My question is I have done extensive research about installing a board. The method I will use is to put one or two galvanised square washers in between the wall and the ledger board to give drainage and allow any dampness to dry out even some DPC may be in order. This seems to be the correct way to do it in the UK. I have seen some instances where you install a flashing over the top of the ledger but most of these would seem to be from the US where timber buildings covered with cladding seem to be the norm and dampness would be a bigger issue. Is this ok ? thanks for any deckbulders advice....

 

[masona]

Are you saying the timber is being fitted below the dpc level ? Not the correct way of doing it, a drawing would be easier to understand. I've read your post earlier and still not quite sure what you mean but there are many way round this problem.

 

[DarrellE]

Thanks for your reply. The deck will be a low level deck which when finished should be at roughly the same level as the back garden . I have dug approx 100mm of a levelled space of 2m x 4.7m to accomodate the deck and also a slightly deeper drainage trench along the house wall end to be filled with gravel to allow adequate drainage. On digging I located the concrete foundations which also stands out about 6 inches proud of the house wall, this is what the ledger will sit on. The house wall begins at the foundations for four courses up to DPC/start of pebbldash. So when the ledger board (144mm) is attached it will sit on the proud foundation lip and extend roughly two courses up. This leaves two more courses until DPC. I am to eliminate the problem rainfall etc. by leaving approx 6mm gap that would be made by the plate washers. I would have thought that to attach a ledger above DPC would encourage damp much more than below. I am no lanscaper so please excuse my ignorance if this is so.

 

[masona]

10mm gap would be better if you can to allow for debris as well. I did something similar using a oversize non-rust nut as a spacer with plate washer on the timber side.

I suppose you could also use the correct paint for wall below the dpc to protect it further.