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***PRICING IS BASED ON $13 PER FOOT FOR A 16 FOOT SPAN. WE CUSTOM MAKE PRODUCT TO ORDER/LENGTH***
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Engineered by Nolan Structural Products
Click Here for the product design report provided by Nolan Engineering, PLLC.
Click Here for the span table
**Tired of bouncy, sagging, or uneven floors?**
Our Floor Joist Stiffening Strap System is a simple, engineered retrofit solution that dramatically improves the stiffness and feel of your floor — without tearing apart your home.
Our Floor Joist Stiffening System is also an ideal solution to strengthen roof rafters to accommodate solar panel installations by securing the steel straps to the bottom of the roof rafters to increase strength, decrease deflection and support the solar panels. The straps come in 3' and 4' lengths to allow easy access to attic space. The straps are secured together at the ends with 8" straps to form a continuous steel band at the bottom of the rafters (see span table).
Use these straps when:
• Floor joists are undersized or over-spanned, causing bounce or vibration
• You notice floor movement or sag under load
• You’re adding heavy furniture, equipment or a kitchen island to an existing floor
• Joists have damage, notches, or holes that reduce capacity
• Limited headroom makes sistering or beams impractical
• You want to preserve finished floors without demolition
• You’re rehabilitating older homes for modern stiffness and comfort
The Problem
Even structurally sound floors can feel weak. Over time, or under heavier loads, you may notice:
• Floors that bounce or shake when someone walks by
• Soft spots or a springy feel in parts of a room
• Floors that sag under heavy furniture like kitchen islands, pianos, or aquariums
• Undersized or older joists that don’t meet modern stiffness expectations
• Cracked drywall, floor tiles, or ceiling joints caused by excess deflection
• Limited space that prevents adding beams or sistering joists
The Solution
The Floor Joist Stiffening Strap System attaches directly to the underside of existing wood joists, forming a tension tie that resists bending and flexing.
Each strap is made from galvanized A36 structural steel and fastened with Simpson Strong-Tie SDS25150 (¼″) structural screws — all included.
By adding this engineered tension reinforcement, your floor’s structural stiffness increases up to 120%, reducing deflection by 35–54% depending on joist size.
**No demolition. No sistering. No new beams. Just engineered results.**
Performance
|
Joist Size
|
Increase in Stiffness
|
Reduction in Deflection
|
|
2×4
|
120%
|
54%
|
|
2×6
|
92%
|
48%
|
|
2×8
|
77%
|
43%
|
|
2×10
|
64%
|
39%
|
|
2×12
|
55%
|
35%
|
• Verified through theoretical and test-based calculations.
• Compatible with 2×4 through 2×12 joists.
• Suitable for residential and light commercial retrofit applications.
Product Features
• Engineered & Tested – Designed by licensed structural engineer Richard Nolan, P.E.
• Easy Retrofit Installation – Fasten directly to existing joists from below
• High-Strength A36 Galvanized Steel – Corrosion-resistant and structural-grade
• Includes Simpson SDS25150 Screws – ¼″ diameter, engineered connection
• Modular Lengths – 3′ and 4′ straps plus 8″ connection plate for variable spans
• Made in the USA
What’s Included
· Floor Joist Stiffening Straps (3′ or 4′ length) for joists up to 16’ in length
· 8″ connection strap for joining 3' or 4' straps together
· Simpson SDS25150 ¼″ x 1½″ structural screws
· 3/8" Nut Driver
· 3/16" Drill Bit
Installation Overview
1. Align straps along the bottom of the joists.
2. Secure using the included SDS25150 screws through pre-drilled holes (2″ spacing).
3. Use the 8″ connector strap to extend length between joists.
4. Repeat for all joists in the affected area for maximum performance.
