power tool reco for 350 sq ft x 10″ area of clayey soil w/ rocks
starting work on a deck / platform that will be flush with the existing lawn and patio. about 2/3 of the lawn will be replaced with a composite deck – an area of about 350 square feet. digging to 10″ to account for gravel bed foundation, deck posts (thinking of using the rigid plastic preformed posts that I see online), 2×6 joists and the deck.
Dug a 5′ x 5′ section with mattock and beneath the top soil its all smooth rocks in clay, from 1″ to 10″. watering the clay works and allows me breaks between digging, but it is still slow and hard work. the back, shoulder and palm are not too excited about this digging work.
So I was thinking of getting a power tool. A jack hammer seems to be overkill but a demo hammer with a clay spade bit could work I think. I would purchase this tool since renting it out would be costlier given that I would work on digging only about an hour each day.
looking for insight or pitfalls on using a demo hammer for this job. Also recommendations on a demo hammer. my budget is ~$500.
Replies
I personally would not make a deck level with the grass. The reason being is the ground water will go to your lowest point which is your gravel base. A step up to the deck wouldn’t be bad and make you endeavor easier on you. I would also just use treated posts, let them dry out before you use them as they are much too wet. Any part that goes into the ground put roofing cement on as an extra protection layer, yes it will get all over you unless you’re extremely careful. It’s what they used on our pole barn and all the guys laughed when I stayed far away. Painter’s disposable coveralls and disposable gloves will help, a lot.
You would only need to dig holes for the posts, making sure you treat the bottom with the roofing cement and a layer of gravel.
I have never heard of using plastic posts to hold a deck up, they’re used to “decorate” and often slide over a 4” x4”. I don’t believe they will be able to withstand the weight of a deck, no matter what it’s size.
If your joists are touching the gravel you will need to make sure they are ground contact rated.
Another alternative would be to use concrete deck blocks. In which case you may not need the posts to hold the joists if the ground is level. Just follow the manufacturer’s specifications for spacing and anything else. I used these when I replaced the old deck around a pool years ago. Our ground was clay with rocks and I wasn’t digging into it in Summer.
I would just rent a tow-behind mini excavator that can walk its way into the area if I couldn't get one of the smaller mini excavators on rubber tracks into the location.
I'm lazy too!