Now is the time to begin making your forms strong enough to hold the weight of the Lag Screw. Starting in one corner, add enough wood stakes, nailing each one as you go to the formwork with 10 penny duplex nails. Steel stakes have pre-drilled holes in them so you simply insert the nail in a hole and drive it in. Continue this until one side is secured soundly. Now stand the inside forms making sure you maintain the minimum width required by your drawings. Install "spreaders" made of scrap lumber across the top of the forms to hold them apart and help hold them from tipping over when the concrete is placed inside. Continue on all the way around the footings until all forms are nailed and staked. NOTE: As you proceed with the formwork, using your level and tripod, make sure the forms are LEVEL! They are of no use if they weave up and down and will make installation of the foundation itself, nearly impossible. If you encounter rock or other obstruction, ask your building inspector how he/she wants to see the footing formed at that location. They may allow you to pin the rebar to the rock, ask that some of the rock be removed to provide a level surface and so on. Now install the rebar. Just slide the long lengths under your spreaders making bends at the corners. Using tie wire, hang the bars from the spreaders so the rebar is located within the bottom 1/3 of the footing height. 12" high footing? Hang the bars 3-4" above the ground. This will help provide the strongest footing you can make. When all rebar is complete, call for inspection and take a rest.
Placing the concrete-When pouring a large footing or foundation, you will most likely purchase the concrete from a Redi-mix concrete supplier. They will want to know, how many yards you need, what strength concrete and what time of day you would like it to be on site. Have your information ready. Order two days before you need it and check again on the day it is supposed to be delivered to make sure there will not be any delays. Weather, plant breakdowns and even manpower can sometimes delay truck delivery times. They will get there as closely to the hour you requested as possible. BE READY! When the truck shows up is not the time to find out you have a flat on the wheelbarrow or can't find the shovels. Have your tools and manpower ready. Most companies allow up to 1 hour on site for unloading. After that you pay additional time charges for the truck and the driver. It can get costly! Unless you are superhuman and very well experienced do not try and unload 10yds of concrete with only 2 people. You most likely will spill more than you use, the concrete will get hard before you finish it and rushing around can cause an injury. Be prepared with sufficient manpower.
After the concrete is placed in your forms and roughly troweled off to the top of the forms, take a few minutes break. The concrete will start to setup and if your plans call for vertical bars in the footings for the new foundation walls, this is the time to install those. They should all be pre-made and laid out roughly where they are to go in the footings. Again, plan ahead. You may "stab" these rebar into the wet concrete, wiggling them around slightly to get the concrete to fill in around the hole you made. Your plans will tell you if the bars go on the inside or outside "face" pf the wall or in the center and how far apart they are to be. "Inside" and "Outside" face simply means the inside or outside of the new all. Most times the bars are to be placed 2" away from the face. Your drawings will tell you this information. Starting in one corner, install one bar in intersection of the corner and then measure whatever dimension the drawing shows for centers. 32" on center (O.C.). Just measure over 32" and install the next bar and so on. When you come to the next corner, make sure one bar is at the corner intersection center again. You can add extra bars of you have a question, just don't add too few.
Next day. Now that you found the muscles you never knew you had (just a little sore?) it is time to strip all the formwork off the footings. Yes all that great form work you did is now just scarp lumber pile material. Take ALL wood out of the foundation area. Rotting wood underground draws termites and other nasty insects! Footings are complete.
Foundation forms completed and filled with concrete. Not child's play!
Foundation walls: Walls may be constructed of concrete block units (Masonry or CMU), poured concrete, pressure treated wood and today even Styrofoam foundation blocks are available. Whatever the type you are using, if you did a good job on your footings and they are nice and level, the walls are going to be easy to install. If your foundation is masonry, your work is done. Your mason will now layout the wall locations, lay the CMU, pour the CMU cells that have the rebar in them and install the straps for the sill plate for the house, shed, garage, etc. Make sure his contract includes all this work and materials. If the foundation is concrete, the concrete contractor will bring all the forms with him. Again, make sure all the formwork, wall ties, rebar required, windows and other accessories are included in his contract. It is possible for a homeowner to form and pour a foundation but it is not child's play. For rentals, rebar installation for the walls, actual placement of the concrete, how to use the trucks properly and possibly the use of a concrete pump are all best left to the pros. Concrete is extremely heavy when wet. Improperly constructed wall forms can result in a "blow-out" of the formwork and serious injury or death can result.
Footings are the basic and first building block of your Hex Lag Screw project. Sheds may sit only on 4 solid concrete blocks but those are the footings. They too must be solid and level to provide a good footing for your shed. Take your time and do it right and the rest of your building will be easier to keep plumb and level.
