How to Support a 32-Foot Sagging Wood Beam

Wood beams

Wood beams can sag if they are undersized for the weight they must carry or the distance they must span. They can sag if damaged by exposure to water, fire or termites. Sagging is an aesthetic problem, but more importantly, it is a serious indication of ongoing structural failure.Wood beams of less than 20 feet can usually be repaired by anyone with an understanding of residential carpentry. Contact a licensed structural engineer to recommend repairs for beams longer than 20 feet. After inspections and calculations, the engineer will recommend replacement of the beam, reinforcement of the beam or adding intermediate columns to support the sag. These recommendations should be summarized in a structural engineer's report.

Things You'll Need

• Structural engineer's report
• Tape measure
• Adjustable steel columns
• Level
• Hammer
• Nails

Instructions

How to Support a 32-Foot Sagging Wood Beam

1. Remove all furnishings, storage or miscellaneous items from the floor that the sagging beam supports. If the beam supports a roof, remove snow and any unattached items on the roof to reduce as much weight from the beam as possible.

2. Use the tape measure to mark locations recommended by the structural engineer to install adjustable steel columns to support the sagging beam.

3. Move the adjustable steel columns to their recommended locations. Hand-tighten the top support plate to gently hold the column in place. Use a level to straighten each column to a perpendicular position.

4. Nail each adjustable column's base and top plates in place. The structural engineer's recommendations will include the number and length of nails and horizontal bracing, if required.

5. Tighten and raise each adjustable top plate as recommended by the structural engineer. Do not reduce the depth of the beam's sag, or attempt to level the floor, without specific instructions from the engineer.

6. Replace items removed from the floor or roof above the beam prior to installation of the columns.

Tips & Warnings

• Check your local building code's requirements before you start. Some code administrators will request to see your structural engineer's calculations.

• Adding support to a 32-foot long sagging wood beam is not a DIY project unless you are a structural engineer. The condition and structural capability of the floor supporting the adjustable steel columns are as important to understand as the condition of the beam itself.

References

• Maximum Spans for Floor Joists
• Adjustable Steel Columns
• Calculating Loads on Headers and Beams

Resources

• Engineered Wood Handbook