Just like the movies-A deck collapse coming soon near you!
Posted by Dan Nugent on
Recently we have been hearing about deck collapses. This is nothing new. Here’s what you can do to ensure all is well on your deck.
What causes decks to collapse? I have done up a sketch to illustrate and act as a glossary only for comments below.
1) Poorly built-Decks are supposed to handle 100 lbs/sq ft or 45.36kg/sq ft. The trouble is older decks may only be able to carry 40lbs/per sq ft. This seems to be more common in aging apartment buildings deficient from the beginning. Metal connectors such as truss hangers deteriorate with corrosion.
2) Poor connection to the house. Lack of the correct fasteners and/or not begin fastened to solid lumber in behind. Special care must be taken if the house is built with structural insulated panels(SIPS).
3) Poor flashing and ledger flashing allowing the ledger board to get wet and rot.
4) Rotten posts and/or beams- check each end of posts for rot and the tops of the beams. Pay careful attention to where wood meets wood-a perfect moisture trap.
5) Beams clad in wood such as cedar boards or Hardie siding (fibre cement board). This traps moisture causes rot that cannot be seen.
6) Carpenter ants-can eat away a ton of beams- usually need wet wood conditions- look for ant movement, signs of sawdust, remove outer wood décor and probe wood with an Awl -also know as an icepick.
There are other causes as well such as poor support for a hot tub, poor or lack of cement footings, too long of unsupported spans. The list goes on. Building a deck correctly is not rocket science, with tons of info even as close as the library, there is no excuse not to build one properly. But it happens all the time.
If you are not comfortable with inspecting the deck yourself, hire someone qualified to have a look, especially if your house is older.