|
||||||||
|
|||||||||
Marking The Location, Clean-up, and Obstacles
Layout your holes using your batter board string lines and a can of red spray paint. If you're using an auger, the soil is going to fly so mark an oversized circle or big "X" on the ground. That way you'll be able to see if the auger needs to be repositioned because it has drifted a bit while drilling. Once the holes are dug, invariably you’ll end up with a few that aren’t quite on center. After the power equipment has the holes roughed out, reset your string lines and check which holes need to be widened and by how much. Make sure to use a plumb bob that you hold up right next to your string lines. Looks can be deceiving. Just standing over your string lines and looking down into the hole doesn't work too well. Mark right on the ground with your spray paint where adjustments are needed.
Once you get the holes in the right location, confirm that you've dug down to undisturbed soil. When the big equipment is done, there will typically be at least of few inches of soil that was loosened but not removed by the auger. Don't be fooled. Power augers leave a layer of loosened soil that has only been slightly recompressed by the weight of the auger on the bottom of the hole. This makes it look like the hole is clean down to undisturbed soil when it’s really not. Always make sure to dig a little at the bottom of each hole with a posthole digger just to make sure all the loose soil is out.
It's not that uncommon to hit at least one really huge boulder right where a footing can’t be easily relocated. When this happens, dig alongside the boulder to make sure it extends below the frost line and then pour the pier right on top of the boulder. In some cases, where the boulder is only partially interfering, you may pour the footing along side the boulder. Cut the concrete forming tube to fit up alongside the boulder and increase the footing thickness. The content under the "How-To" menu is a small sampling of all the material covered on BestDeckSite. For immediate access to in-depth information on excavation, frost heave, soil bearing capacity, and sizing footings, as well as, comprehensive coverage of all aspects of gazebo and deck building, get a password and log-in now. Footings
|
|||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||
|
Tip: Especially if you bring in power equipment to dig your holes, be prepared to do some
raking and grading. The soil really flies when the equipment goes to work and you’ll want
to make sure to rake off the lawn any soil that lands outside the deck perimeter
- to keep the grass from being killed. Likewise, make sure to re-pile your lumber in a new location every few days or else you’re
going to end up doing some reseeding later on.
Check Point - The bearing strength of soil varies depending on it's physical
make-up. For example, although heavy clay soils are difficult to dig they are some of
the weakest soils and require the largest footings. When footings are undersized, the deck or gazebo
supports will sink over time causing the flooring surface to become uneven and
putting excessive stress on the connection to the house.
When you 
Note: By International Residential Code (IRC), the bottom of footing holes may not be sloped
more than 10%.
Believe it or not, I actually read a story about a guy who
reached into a deep footing hole he'd dug, slipped, and got stuck. His buddy had
left to pick up supplies just a few minutes prior, leaving this poor fellow hanging
upside-down. Eventually, after quite a while and more than a few moments of panic, the trapped
builder was able to back his way out of the hole inch by inch.
Not fun.
