- What size tube 6", 8", 10", 12"?
For average domestic deck or out-building 8" or 10" will suffice - 12" is a big tube requiring a lot of concrete to fill - 6" not recommended for any application. Remember, the smaller the tube diameter, the smaller the target to land deck posts on.
- Can masking tape be used to attach REDIBASE?
Yes, providing concrete pour is not delayed more than 24 - 36 hours. Any 2" + wide tape can be used, but duct tape is strongest and easiest to work with. REDIBASE has been attached using screws but tape is much stronger and faster.
- How deep should the footing be?
Depends on climate, depth of ground freeze, soil type, subject to flooding, etc. Check local codes with your building inspector or local lumberyard. North East U.S. climate depth should be 4 to 5 feet. Remember, columns covered by a structure will be subject to deeper freeze because of lack of snow cover. Columns for wind tie downs, as deep as possible.
- Should I dig by hand or hire a excavator?
Anything beyond 3 feet deep, or more than 3 - 4 columns definitely hire an excavator. Utilizing an excavator 6 or 8 columns can easily be installed, backfilled and poured in one morning.
- Should excavation be continuous trench or individual holes?
Trench excavating is only required in extremely heavy, non draining clay soils or sub-soils. In normal draining soils, individual holes are adequate.
- Is there any way to lessen the number of posts required for a deck?
Yes. By cantilevering the deck over a heavy beam.
- What can be done to discourage frost from adhering to the column?
Apply 5 or 6 wraps of 6 ft wide heavy clear polyethylene around entire length of column before backfilling.
- Should I backfill with material other than what was excavated?
Only in extreme cases of very heavy clay where trenching, gravel and tile drain may be required. In most instances, wrapping the column in plastic and backfilling with excavated material is sufficient. Never backfill with porous material (gravel - crush stone) in heavy clay soils unless provision is made to drain water away.
- Should a mechanical tamper be used to compact backfill?
No never, construction tube may collapse. Tamp with foot pressure only as backfilling proceeds. Mound backfill 2 - 3" above grade, around protruding columns to allow for ground slump (settling).
- Are steel reinforcing bars needed?
Not for domestic decks, but check local codes. We recommend one 1/2" bar driven 8 - 12" into the sub-soil below the footing, centered in the protruding tube. (easily done after backfilling) When concrete cures, cut rebar off 2" above concrete to serve as a locating pin for deck posts. Unreinforced REDIBASE has been hydraulically tested to 25,000 lbs + without failure. (see Technical Info)
- After backfilling, do the forms need to be filled with concrete
No, concrete pour may be delayed a few days to a week. (under normal to dry conditions) (depending on tube quality) Fill before ground slump (settling) occurs.
- Should we mix concrete ourselves or buy trucked in wet redi-mix?
Depends on number of posts. But no hand mixing beyond 3 -4 posts. In many areas, small batch redi-mix trucks are available. It takes a lot of 80 lb. bags of dry pre-mixed concrete to fill an average 4 foot column and footing. One REDIBASE and 4 of 8" tube = 5+ 80 lb bags dry mix concrete. (see VOLUME)
- Should concrete columns come right up to the deck?
Only if deck or structure bottom is 10" or less above the ground level (grade). Finished columns should end 3" - 4" above ground and support deck with center pinned 4 x 4, 6 x 6 or 8 x 8 wooden posts up to deck. Never attempt to run columns 3 or 4 feet above grade. Unsightly, unstable and difficult to later attach lattice work to.
- Is any special fixture required to attach wooden posts or beams to
concrete column tops?
No, not structurally, normally posts are simply placed over re-bar locating pins protruding out of the concrete (see 10). (Flood or earthquake areas may have different codes.) A positive attaching system must be employed when columns primary functions is as a wind resistant tie-down. Embed positive attaching in wet concrete.
- How long must concrete cure before building structure?
Concrete should be let cure for 48 hours before loading. You can however start framing structure immediately after backfilling if you prop up frame on temporary shoring.
- Should the tops of all the concrete columns be poured level to each
No, unless finished grade is level. Columns should always protrude 3 - 4" above grade, even on a sloping grade. Make up different distances to deck with wooden posts. Respect footing depth when following a slope.
- Do I have to install 2 columns with footings to support the bottom of
stairs to the deck?
This is seldom done, usually stairs are attached using heavy duty hinges to allow for frost movement.
- How do I remove REDIBASE after concrete cures?
You cant, and you dont, it stays in the ground.
- Do I remove the construction tube?
No, but peel paper back to ground level (esthetics)
- Do decks have to be built of pressure treated or decay resistant woods?
Yes, absolutely yes, no amount of paint or preserver will maintain an exposed deck for any length of time.