Chapter 7: Basement Floor

1. Introduction

The basement flooring is poured concrete. While the actual flatwork is completed by professional contractors, the preparation work for the cement pour is the responsibility of the Habitat volunteers. The basement floor preparation is key to having proper floor drainage and to minimize cement floor cracks and other flaws. The floor will require proper grading, trenching for plumbing and sump pump installation, gravel preparation, wire reinforcement installation and installation of a plastic vapor barrier.

2. Safety Issues

• Care should be taken to avoid falls.
• Wear hard hats while working in the basement.
• Follow ladder safety guidelines.
• Gloves should be worn while using shovels, rakes, and pick axes.

3. Prior Tasks to be Completed Before Starting

• Foundation poured, stripped, snap ties removed, braced if necessary, and backfilled.

4. Recommended Staff/Crew Assignments

• 3-5 people to clear excess concrete from foundation pour and to grade dirt floor.
• 4-6 people to spread gravel across floor.
• 3-5 people to install wire reinforcement and vapor barrier.

6. Tools/Equipment List
Tools & Equipment Needed at Each Site:

• Rakes
• Shovels
• Pick axes
• Wheel barrow
• Extension ladders
• String line
• Caulking gun Tools Each Crew Member Will Need:
• Gloves
• Safety glasses
• Hard Hat

7. Material List

• Fill Gravel
• Plastic sheeting
• Silicone caulk

8. Quality Checkpoints
____ Gravel fill level and at proper height on floor
____ Plumbing and sump pump rough outs complete
____ Sump pump rough outs clear of debris

9. Construction Drawings and Text

NOTE: The following drawings, diagrams, and text are to be used on the job site when a question arises as to methods and procedures associated with the task. The notes on the drawings have been geared toward use as a quick reference. If a more in-depth explanation is needed, please read the text description. But most importantly, consult your Habitat Site Supervisor and Construction Manager for advice as needed.

1. Preparing Basement Floor:Begin basement work by first removing all excess concrete from the foundation pour. Most of the excess concrete will be found near the footings for the beam poles and around the foundation walls. In addition, remove any wood forms, stakes and loose rocks that may have accumulated in the basement.

After the excess concrete and other debris has been removed from the basement, the next task is to properly grade the basement floor. The goal is to have at least 4" of gravel fill throughout the basement floor. Remove and spread dirt from the basement floor with shovels and rakes to accommodate the 4" gravel fill. While grading the dirt floor, trenching for the plumbing and sump pump locations must be dug. Depending on the condition of the soil, a pick axe may be required to break through the soil for the trenching and sump pump hole. The plumbing contractor is responsible for marking the location for the trenching and sump pump rough outs. If these markings have not been completed or are not obvious, consult with the Site Supervisor or Construction Manager for the exact locations for the plumbing and sump pump.

2. Gravel Fill Installation:Once the floor has been properly graded, gravel fill should be added throughout the basement to provide at least a 4" fill. The gravel is typically delivered to the job site by one of the Habitat Construction personnel, and dumped into a pile in the basement. Use shovels, wheel barrows and rakes to spread the gravel evenly along the basement floor. The gravel should be spread across the floor so that it is level with the top surface of the footing along the basement foundation. A string line may be used to verify a consistent height of the gravel across the floor. Make sure the gravel is not spread on top of the drain pan that runs along the top of the footing.

3. Plastic Vapor Barrier Installation:

A plastic vapor barrier is installed on top of the gravel fill to provide a barrier for radon gas containment and proper ventilation through the sump pump system. Provided the plumbing has been installed, the plastic vapor barrier should then be installed over the gravel fill throughout the basement floor. Install the plastic vapor barrier to minimize the number of seams between pieces of plastic. Overlap the seams and caulk the seams with silicone caulk to provide an air tight seal.

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