Sandersfire International


Firecrete Mixing and Installation

Mixing Procedure

Mix with clean water in a plastic container. Slowly add the dry powder to water while stirring by hand or power mixer to ensure a smooth lump-free mix.

Recommended Mixes

Dry Powder : Water ratio
By VolumeFirecrete STDFirecrete HSFirecrete HD
Pourable / floors 21/2 : 1 3 - 31/2 : 1 4 - 41/2 : 1
Stiff / walls 3 : 1 4 : 1 5 - 51/2 : 1
By WeightFirecrete STDFirecrete HSFirecrete HD
Pourable / floors 1.3 : 1 3 : 1 7 : 1
Stiff / walls 1.9 : 1 3.5 : 1 10 : 1


Do not attempt to extend working time by remixing with more water after the mortar has started to set, as this will interfere with the setting process. Always mix in clean buckets.

Using dirty buckets containing remnants of mortar from earlier mixes, will accelerate the setting process and may reduce working time to as little as 10 minutes.

The wet mix will remain useable for approximately 45-60 minutes depending on batch size, water content and temperature. Any spillage should be wiped up with a damp cloth before setting occurs.

Floor Openings

When sealing holes in floor slabs, appropriate shuttering must be installed, cut to fit tightly around any services within the opening, to support the wet mix until it sets. Non-combustible shuttering materials, such as mineral fibre slab, can be left in place, but combustible materials must be removed, after the mix has set. For complex penetrations it may be preferable, to initially form a thin seal around all services, with a nominal 5mm layer of the mortar mix. Once this has set, the remaining depth of seal, should be poured in one operation.


As the load bearing performance particularly in un-reinforced situations is dependent on compressive membrane action against the concrete slab edge or other rigid boundary, it is essential to check that this is vertical, before commencing installation.

Building up the seal in several operations with the individual layers being allowed to set, will result in a weak laminated structure with severely reduced load bearing performance.

Cutting out part of the finished seal to accomodate services, must not be undertaken without review by a competent person, of the effect on the structural integrity of the seal.

Wall Openings

For small holes and gaps, trowel a stiff mix into the opening to the correct depth. For larger holes, use an appropriate damming material to support the mix until it sets, or, if a fair faced finish is required to both sides, consider using a sandwich construction. Alternatively, the mortar may be pre-cast into convenient sized blocks, a stiff mix being used as a bedding mortar.


Number of 20kg bags per m2 at 100mm thick:

Firecrete STDFirecrete HSFirecrete HD

Thickness/Fire Rating

Refer to test data or manufacturer's recommendations.

Health and Safety

Contains gypsum plaster and natural, or heat processed aggregates. Wear appropriate protective clothing, including gloves, dust mask, safety glasses, especially during mixing, to guard against dust inhalation, eye damage and skin irritation. For further information, please refer to the Material Safety Data Sheet, available on request.

Packaging and Storage

Supplied in 20kg bags which must be stored in dry conditions. Shelf life, in unopened bag, at least 6 months.

Customer Service

For additional technical help, or to obtain copies of our structural and fire test reports, please contact our Technical Department.

Liability Exclusion

Sandersfire International will not be held responsible for failure of the product to perform nor for any claim in respect of health and safety, if the product is not installed strictly in accordance with these instructions, guidance and warning notes.