Made in the USA • Patented • Jobsite-Proven • Non-conductive • Non-corrosive
What Is the Adjustable JAWS® Small Concrete Screed Support Kit?
The Adjustable JAWS® Small Concrete Screed Support Kit is a complete bundled MAKO system designed for fast, accurate grade setting using 2x4 wood screed rails and aluminum or magnesium rails up to 1-1/2″ (40 mm) wide.
This kit combines JAWS® Small Screed Chairs, FinStand® Adjustable Supports, and Base Plate 4.5® to create a stay-in-place, height-adjustable screed support system for vapor barriers, concrete overlays, sand/rock subgrades, elevated decks, sloped slabs, bridge work, and super flat floor projects.
Threaded rods (all-thread), hex nuts, and flat washers are sold separately.
What’s Included
-
100 JAWS® Small Screed Chairs
-
100 FinStand® Adjustable Supports
-
100 Base Plate 4.5®
Designed For
- Vapor barrier slabs (membrane-safe Base Plate)
- Concrete overlays
- Slabs on sand or rock sub-grade
- Elevated decks (wood or metal)
- Sloped slabs and grade transitions
- Bridge decks, waterways, and power plant projects
- Super flat floors requiring FF/FL compliance
Ideal for use on super flat floors to stay compliant with ACI 302.1R-04, ACI 117, and ASTM E1155. Iowa DOT approved.
System Compatibility
-
Screed Rail Supported: 2x4 wood screeds and aluminum/magnesium rails up to 1-1/2″ (40 mm) wide
-
JAWS Mounting Range: Fits rebar or rod 3/8″ to 5/8″ (10–16 mm)
-
Threaded Rod: FinStand uses 1/2″-13 all-thread (cut to length based on slab depth)
-
Vertical Adjustment: Up to 1-3/4″ (45 mm) using nut and washer
-
Spacing Guideline: Place supports every 3–4 ft (1 m) depending on rail length and sub-grade conditions
Key Specifications
-
Minimum Assembly Height: Using a wood 2x4 from the bottom of the Base Plate to finished elevation is approximately 6-3/4″ (171 mm) (Base Plate + FinStand + 2x4 rail configuration)
-
Load Capacity: Holds up to 1,000 lbs (system-dependent and per product ratings)
-
JAWS Feature: Internal “fins” hug rebar/rod to prevent bounce-off during placement
-
Base Plate Feature: Will not puncture vapor barrier; textured underside grips adhesives; can be secured with screws, nails, construction glue, or other adhesives
-
Material: Impact-resistant medical grade polypropylene (non-metallic)
-
Coverage: 100 JAWS Small + 100 FinStands + 100 Base Plates per box (approx. 3,000 sq ft / 278 m²)
-
Rod Guidance: Use steel threaded rod for slabs over 8″ (200 mm)
-
Threaded Rod / Hardware: All-thread, hex nuts, and flat washers are sold separately. Rod length determines finished slab height (see slab depth chart).
Compliance, Approvals & Patents
-
Standards: ACI 302.1R-04, ACI 117, ASTM E1155
-
Approvals: Iowa DOT approved (other states pending)
-
Patents: 8,096,182 | 8,544,182 | Patent Pending
How It Works
- Place Base Plate 4.5 on vapor barrier, overlay surface, sand/rock base, or other substrate.
- Snap FinStand into Base Plate until securely locked.
- Insert 1/2″-13 threaded rod (sold separately), cut to slab depth.
- Adjust height up to 1-3/4″ using nut and washer.
- Install JAWS® Small onto rebar/rod (3/8″–5/8″ range).
- Place 2x4 wood screed rail (or rail up to 1-1/2″ wide) into JAWS teeth.
- Space supports every 3–4 feet and begin concrete placement.
For slab depth and all-thread length selection, refer to the FinStand slab depth chart in the FinStand Product Data Sheet. For slabs over 8″ (200 mm), steel threaded rod is recommended.
Why Contractors Choose This Kit
- Complete adjustable 2x4 screed system including vapor barrier-ready Base Plate
- Stable setup on membranes, overlays, sand, and rock
- Adjustable grade control for slope changes and deck variation
- Non-conductive and non-corrosive for extreme environments
- Engineered for consistent results on super flat floors
Frequently Asked Questions
Does this kit include threaded rod, nuts, and washers?
No. Threaded rods (all-thread), hex nuts, and flat washers are sold separately.
Can this be used on vapor barriers without puncturing the membrane?
Yes. Base Plate 4.5 is designed to sit on vapor barriers or membranes without puncturing them.
How far apart should I place supports?
Typically every 3–4 feet depending on rail type, screed length, and sub-grade conditions.
When should I use steel threaded rod?
For slabs thicker than 8″ (200 mm), steel threaded rod is recommended.
Does the MAKO® Driver work with JAWS® Small?
Yes. The MAKO® Driver works with JAWS® Small to provide faster, more consistent setup when aligning to string line or laser finished elevation.
Recommended Add-Ons
-
Nylon or Steel All-Thread (1/2″-13) – Cut to slab depth
-
Hex Nuts + Flat Washers – Required for fine-tune adjustment
-
MAKO® Driver – Speeds up and standardizes setup
Downloads
JAWS® Small Product Data Sheet
FinStand® Product Data Sheet
Base Plate 4.5® Product Data Sheet
