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Footings & Foundation

Temporary Services | Surveying and Layout | Excavation | >>Footings/Foundation |  Foundation Options | Subrough Plumbing & HVAC | Dampproofing, Waterproofing and Window WellsWater and Sewer Laterals | Foundation Drain, Backfill and Rough Grade |
Basement Slab

Intro
The footings are the portion of the foundation that transfers the weight of the structure to the soil. Generally the footing and foundation will be built by the same contractor. After the the excavation is complete you are ready for the footings. The footings are generally made of concrete with steel reinforcement. Most residential footings are between 16"-24" wide and 8"-12" thick. The width of the footing helps spread the weight of the house to prevent excessive settlement.
Steel reinforcing bar also called rebar is run horizontally through the footing for added strength. The rebar is overlapped and tied together. "L" shaped rebar is placed vertically into the footing after the concrete is poured with about 2' sticking above (click on photos icon to see example). This rebar strengthens the connection between the foundation walls and the footings.

The footings are formed with 2 x 8 or 2 x 10 boards (laid on edge) and held together with stakes on each side and straps or longer stakes across the top. Once the footings are connected they are set to grade with a laser level or transit. Setting the footings to grade is the process of leveling them. If the footings are not set to the same height the house will not be level (flat).
After the footings are formed and reinforcement placed they are inspected by the building Inspector. The footings are poured and the concrete is allowed to cure for a day. The forms are then removed and reused on another jo
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It is probably a good idea to hire a foundation contractor that will pour both footings and foundation. Sit down with the contractor and review the plans for special problems.

Costing and Estimate
Footing and foundation contractors generally price the job by the size of foundation, the number of corners in the foundation, the number of windows and doors in the foundation walls, and the height of the walls. The following items should be agreed upon in the contract/specs:
Price for the job.
• Price for change orders.
• Hourly charge for work not covered by the contract.
• Description of work to be performed.

Specs to include:
• Type and strength of concrete mix to be used. (compressive strength, slump, etc). Or if block, the size of block, the grouting requirements, and the reinforcing required.
• Type and size of anchor bolts, and hold down straps and their respective locations.
• Requirement that the foundation walls be mechanically vibrated.
• Size and amount of rebar to be installed in the footings and foundation (this is usually specified by the local code and shown on the blueprints).
• Engineering calculation that pertain to the footings/foundations.

Inspection
It is critical that the footings and foundation are constructed according to the foundation plan. Make sure that they conform to the plans. Check the foundation walls for square. Most foundations are not perfectly square (as framers will tell you). A foundation that is slightly out of square (1-2 inches) is usually not a major problem. Use a transit or laser to check the level of the foundation. It should be within 1/4" inch throughout the structure. The framers can compensate for a foundation that is slightly out of level, but most won't know if it is "out" unless you check it.

Safety and Security
Keep the site secure especially during the footing and foundation construction. As soon as the forms are stripped here are some of the tasks to follow (see construction schedule):
• Have truss maker measure for trusses.
• Have the framing lumber package ready for delivery.
• Have the excavator ready to begin the backfilling, installation of water and sewer laterals and the rough grade.
• If the foundation is a basement the sub-rough plumbing and heating can begin.
• Complicated foundation designs cost more. The more corners in the foundation the higher the cost.