The Wafflemat™ Foundation Forming System
On-grade Mat Foundation for Expansive, Collapsible and Rocky Soils
Upfront
• The Wafflemat Foundation-Forming System
–
–
–
–
–
–
–
What it is – and isn’t
Features
Typical installation steps
‘How To’
Photo Sequences
Technical resources
Contacts
Best Base Confidential. All Rights Reserved.
2
Description
• What it is
– Elevated post-tension slab (4” to 6”) poured monolithically over either
8.5” or 12” high, 19” x 19” foundation forms (‘Waffleboxes’), which
provide void space for movement of soils
– A series of ribs, 3’8” on center, are created by inter-connecting the
foundation forms
• What it’s not
– Slab resting entirely on grade, made entirely of concrete, without a
place for movement of soils
– Dirt-formed rib system requiring significant trenching and construction
Best Base Confidential. All Rights Reserved.
3
It is
is not...
5
Section View
Top View
Cross Section
Best Base Confidential. All Rights Reserved.
6
Features
Design:
–
Use on expansive, collapsible, and rocky soils.
Performance:
-
Voids resist swelling from over-watering, surface drainage, and flooding. Ribbed footprint
means less contact with soil, yet extremely stiff slab. Prefect placement of cables equals
minimum sag/additional strength. Acts as built-in vapor barrier.
Implementation:
–
No presoaking pads, no trenching for concrete beams, no footings, no earth spoils and offhaul. Less depth of trenching for plumbing laterals beneath foundation forms. Quick -- and,
fool proof -- set up/installation.
References:
-
Millions of sf residential & light commercial space installed since 1995 in most difficult soil
conditions in US and Mexico without one structural callback/failure.
One More: Made of “green” (re-cycled polypropylene plastic) materials
Best Base Confidential. All Rights Reserved.
7
Typical Installation Cycle
• Day 1: Form boards set, plumbing installed, inspection
• Day 2: On-grade mat foundation forms (‘Waffleboxes’) spread
and clipped/connected
–
–
–
–
Two sizes of void boxes; 8.5” uses plastic clips, 12” metal clips
Place tendons/anchor bolts
Set interior form; i.e., garage firewall / porch
Inspection
• Day 3: Slab poured
– Strong enough for crew to walk on
Best Base Confidential. All Rights Reserved.
8
‘How To’
• Estimate number of Wafflebox foundation forms in footprint
- Take total sf of footprint, divide by 4.15
- Example: 1500 sf / 4.15 = 361 Waffleboxes needed
• Calculate number installed per man hour
- Detailed survey of last 15 projects; most 175 per man hour, least 28 per man
hour, average 75 per man hour
• Determine yards of concrete in a Wafflemat slab
- 28 sf per cubic yard using 8.5” Wafflebox w/ 5” slab
- Example: 1500 sf / 28 = 54 yards
Best Base Confidential. All Rights Reserved.
9
Setup
Setup
Groups of two/four Waffleboxes clipped & connected
12
Slab Pour
Finish
5,000 sf house in Hawaii
Note: Plumbing already up
16
Waffleboxes left out for point loads
17
Cables in Clips
Strong enough to walk on
Working in Hawaii
Waffleboxes ‘lock’ when concrete poured
Used on Multi Levels
Finished House
Technical Resources
• Wikipedia: http://en.wikipedia.org/wiki/OnGrade_Mat_Foundation_for_Expansive_Soils
• Google: ‘On-grade mat foundations’
• Best Base Website  ‘Technical Papers’
– Wafflemat Slabs Provide Superior Performance
– Lowering the Carbon Footprint When Using the Wafflemat System for Concrete
Slab Foundations
– Wafflemat System Design Considerations
– Wafflemat FAQ
– Thermo Mechanical Analysis of Wafflemat Samples
– Wafflemat and the IBC
Best Base Confidential. All Rights Reserved.
24
Contacts
• www.thebestbase.com
• Tom Richards, 925.683.2739
• Jim Winslow, Implementation: 925.352.2456
• Rich Treanor, Planning/Production: 925.640.8680
• Tom Bragg, Engineering Liaison: 925.915.0808
• John Cook, S.E.: 707.578.8185
• Dan Rhoades, G.E.: 925.932.1177
• Greg Carr, P.E.: 925.336.6366
Best Base Confidential. All Rights Reserved.
25