Wood decks and stairs are susceptible to rot and water damage. Use lag bolts to raise deck posts and stair risers above footings to prevent water from seeping into the wood.
Use your impact driver to drive 2 1/2” lag bolts into the base of your wood project and leave about 3/4” of an inch of space between the head of the bolt and the wood. This space will keep the wood from soaking up water and also provide an easy way to fine-tune the level of the posts by screwing the lag bolts in or out.
Another way to protect your wood from moisture is to wrap the ends with Blueskin membrane. This self-adhering waterproof membrane provides another layer of protection for your wood which will make it last longer.
Combining these two moisture prevention tips can help extend the life of your deck by years.
Add 10 years to the life of your deck | The Samurai Carpenter (YouTube)
via Lifehacker
Use Lag Bolts to Extend the Life of Your Outdoor Deck