FIRMAMENT or FM is a concentrated organic enzyme that stabilises and hardens soils through a catalytic binding of soil particles. The permanent bonds formed by the FM produces a high density, water impermeable, high road bearing capacity and long lasting base for roads. It is made using a proprietary Fermentation of Crop Biomass, similar to Beer Brewing and has been used in North America since early 1970's and in Asia since 1996.

What is firmament or FM?

  • A concentrated organic enzyme that stabilizes and harden soils through a catalytic binding of soil particles. The permanent bonds formed by the FM produces a high density water impermeable, high road bearing capacity and lasting base for roads
  • Used in North America since early 1970's and in Asia since 1996
  • Made using a proprietary Fermentation of Crop Biomass, similar to Beer Brewing.

Benefits of Firmament

  • Non-corrosive, non-toxic, non-flammable and ENVIRONMENTALLY SAFE
  • Cost effective – costs approximately 25-50% of a traditional surfaced road
  • Reduces the need for expensive aggregate
  • Reduces labor and maintenance
  • Can be surfaced with cement, asphalt, or Chip Seal
  • Fast to build – complete curing takes 72 hours
  • Higher Density
Soils/aggregates in FM-stabilized bases are tightly bound together by FM. The entire mass is hardened into a slab with enough rigidity and strength to spread loads over a large area of the subgrade. Unstabilized granular bases concentrate loads on a small area.
Pavement core proves strength of FM. Even in severe climates the strength of FM increases due to continued cement hydration.
New Zealand permeability test on FM treated soil. Moisture can infiltrate unstabilized bases through high water tables or capillary action causing softening, lower strength, and reduced modulus. FM stabilization reduces permeability, helps keep moisture out, and maintains a high level of strength and stiffness even when saturated.

FIRMAMENT Soil Requirements

  • Will not work with high organic soils such as peat or loam.
  • Will not work with pure sand minimum 8-11% cohesive fines required


Step One

Step One

Analysis of soil samples for Soil type, Plasticity, CBR, Shear
Step Two

Step Two

With Grader/Scarifier, loosen 20cm of the road surface and break the soil into a homogeneous state.
Step Three

Step Three

Calculate amount of FM needed:
  • Example: Assume road 1,000m long, 15 m wide, 0.15 m depth
  • Soil Volume:1,000m (L) x 15 m (W) x 0.15m (D)= 2,250 cubic meters
  • Amount of FM needed: • 2,250 cubic meters x 0.05 = 112.50 liters of FM needed
  • Dilution of FM -the amount of water needed to dilute the FM depends on the dryness of the existing soil

​Rules of Thumb when diluting FM
  • If the existing Soil is DRY mix 700-1,000 parts or more of water to 1 part FM
  • If the existing Soil is NORMAL to WET, mix 500-700 parts of water to 1 part FM
  • Do NOT use more concentrated than 1:500 as water is needed to disperse FM into the soil
  • 1 litre FM can produce 133 square meters of road surface (15 cm thick)
  • Put water into the tank first then pour in concentrated FM-- doing the reverse will create a lot of foaming.
Step Four and Five

Step Four and Five

Spray diluted FM evenly onto loosened 20 cm depth of soil over the surface area mapped out.
Alternate spraying/soil mixing over the specified area until all the FM solution is depleted and evenly mixed into the soil.
Step Six

Step Six

Allow soil to dry until almost optimum moisture (OM). Soil at OM when molded into a ball will crumble into large pieces when handled. After OM is reached, configure the drains and road camber/crown to prepare for final compaction.
Step Seven and Eight

Step Seven and Eight

Using a vibrating compactor, begin compaction from the outer edges and work towards the middle. Once several passes have been made, turn off the vibration and smooth roll to a final finish. Not turning off the vibration during smooth rolling will crack the uncured FM.


  • Before spraying of FM, Calcium in the form of agricultural lime or cement powder is sometimes recommended where flooding have produced low-quality soils where vital calcium or other minerals have leached out. Addition of one kilogram per square meter will add only a few cents to the road cost but will go a long way to guarantee enough calcium and speed the soil bonding to provide additional strength to the road.
  • If it rains before compaction, work should be stopped. Any rain after compaction will have no effect because the surface is sealed.
  • On day two, smooth roll the road again to a final smooth and clean finish. If the road was damaged overnight, just re-camber the road with the grader and smooth roll again.
  • FM roads cures over a period of 3-4 days depending on the humidity and rain. The road can be reworked for several days by just spraying plain water to keep the necessary moisture in the mixture. Hardening of FM roads continues until nearly all moisture has evaporated from the treated layer in 30-60 days. The rate of hardening as measured with a penetrometer increases dramatically from day two to day four, after which the rate is more gradual.
  • Measured with a penetrometer, the unconfined Compressive Strength of an FM road after four days is beyond 22 Kg per square meter (or 22 tonnes per square foot). The penetration force exceeds 36 kg per square centimetre.