---
title: "Combimix_CM700_PBD_120103"
url: https://stacklist.com/card/c74cee95-f46e-419d-8a18-b97fc56d0b80
stack: https://stacklist.com/c/business/stack/6ef6e379-b702-4156-8fa8-00346fb192a1
summary: "Combimix CM 780 Fiber Basic is a premium calcium aluminate cement-based self-leveling underlayment reinforced with fiberglass for creating durable, flat surfaces on various substrates. The product requires proper substrate preparation, specific mixing ratios, and careful application techniques to achieve optimal performance and LEED compliance."
tags: "underlayment, calcium-aluminate-cement, self-leveling, flooring, construction, leed, fiber-reinforced"
key_entities: "Combimix AB (organization), Bålsta (location), Sweden (location), CM 780 Fiber Basic (technology), LEED points (concept), calcium aluminate cement (concept), PP 600 primer (technology)"
classification: "reference"
content_hash: "sha256:5d4d8ec411740a9b5fbea69326cd2c33a58f2e1d433c55febed7848172a66ed0"
acp_version: "0.2"
token_counts_approximate: 1904
visibility: public
agent_accessible: true
status: "final"
---

# Combimix_CM700_PBD_120103

Combimix datasheet 
Combimix AB • Verkstadsvägen 6 • SE - 746 40 Bålsta • Tel. +46 (0)171-46 65 90 • info@combimix.com 
Contributes to LEED points
Area of use 
Combimix CM 780 Fiber Basic is a premium quality calcium aluminate cement based self-leve-
ling underlayment that is reinforced with fibreglass filaments for added strength. The product
is intended for indoor use to create a new durable, flat and smooth surface on substrates of
concrete, lightweight concrete, stone, ceramic tiles, gypsum boards, quarry tiles, cement or
epoxy-based terrazzo, wood and well bonded VCT or VAT. When applied on wood subfloor,
reinforcement mesh must be used. CM 780 Fiber Basic is specially designed for thicker instal-
lations. The product is intended to be covered with a top layer, e.g. tiles, carpets or similar. The
CM 780 Fiber Basic can be covered with most floor coverings after 1–3 days depending on the
installation thickness. 
Pre-treatment 
The substrate should be clean and free of dust, cement skin, grease and other impurities that
can prevent adhesion. Adhesion and surface resistance of the substrate should be no less than
72 psi. Always prime the substrate with PP 600 and allow to dry before pouring (see PP 600
datasheet for proper dilution and installation directions). In terms of the primer forming a film,
the temperature of the substrate must not be below 50 °F. For best results, the ambient tempe-
rature in the work area should be between 50 and 77 °F. At higher or lower temperatures, the
time for curing will shorten or extend. Protect the product from excessive heat, excessive cold
and draft conditions during and after the installation. It is recommended that the installation
should be done with a proper air ventilation from an HVAC system. With the risk for cracks due
to shrinkage or settings in the subfloor, a concrete surface should not be leveled within the first
28 days after casting. As a recommendation the RH in the concrete should have reached RH 90
% as the upper limit for pouring the CM 780. Use the Combimix form foam for edging. In order
to avoid drainage pipes from getting clogged, always make sure the drains are properly sealed
before pouring. 
Mixing 
Mix the dry powder with max 3.6 qt (3.8 L) of water, max 18 %, per 44 lb (20 kg) bag. 
Manual mix: Mix with a heavy duty ½” (13 mm), 650 rpm minimum drill and a whisk to obtain a
lump free consistency. 
Mixing pump: Mixing pump intended for this purpose. Start pump at minimum of 125 gallons
of water per hour and adjust as necessary to yield a self-leveling consistency. Please note that
the production capacity and speed of the pump will dictate the gallons of water ratio per hour.
The Combimix slump test must always be carried out to ensure the product performance and
that the mixture is homogenized and free from separation. The correct water mixture can be
tested using a slump test with a cylinder with Ø 1.18” and a height of 1.97” (Ø 30 mm and a height
of 50 mm) on 11.8” x 11.8” (300 x 300 mm) plexiglas plate. With the correct water mixture, the
spread should be max 5 5/16” (135 mm) for application thickness 1/4”–4” (6–102 mm) . The slump
test also checks that the material is well blended and that there is no separation. 
Application 
The mixed material is applied by hand, or pumped onto the substrate in lengths. Each new rib-
bon is added to the old one as soon as possible so that the material can blend together and
create an even surface. The width of the ribbons can be adjusted to the capacity of the mixing
pump and the thickness of the covering. The material requires a light treatment with a toothed
trowel to provide maximum smoothness. Working time of the product is apx. 10 to 25 minutes.
Application thickness 1/4”–4” (6–102 mm). 
Post-treatment and curing 
You can easily shape or cut the semi-hardened self-leveling underlayment material before it fully
dries. Protect the surface for up to 24 hours after installation. Material can be walked on after 1–3
hours. Combimix recommends that no sweeping compounds be used on products after instal-
lation is complete. A simple dilution rate of 1:5 primer PP 600 and water can be used to minimize
dust if necessary. Apply it with a high pressure pump type sprayer. Always make sure that the
material is sufficiently dry before it will be covered. The guided time for dehydration down to RH
85 % of the product is 0.39” (10 mm) per week. The guiding value assumes a curing temperature
of approximately 68 °F, 40 % RH and proper air flow.
NOTES: This product is not intended to be used as a wear surface. It is also not intended for
exterior use. This product is not a vapor barrier and will allow free passage of moisture. Follow 
Coverage per 44 lb. (20 kg) bag 
1/4 ” (6 mm) thickness
1/2 ” (12 mm) thickness
3/4 ” (19 mm) thickness 
apx. 2 0 sq. ft. (2.0 m 2 )
apx. 11 sq. ft. (1.0 m 2 ) 
apx. 8 sq. ft. (0.8 m 2 ) 
Technical information 
Compressive Strength
(ASTM C-349-02)
5,400 psi
Flexural Strength
(ASTM C-348)
945 psi
Fire standard (EN 13813) A1 fl
RWFC 550
Tensile Bond Strength > 217 psi
Surface Tensile Bond
Strength (7 days)
> 217 psi
Substrates Concrete, lightweight
concrete, stone,
ceramic tiles, gypsum,
wood, quarry tile,
cement- or epoxy
based terazzo and well
bonded VCT or VAT
Pour depths 1/4”–4”
Weight (dry state) 111 lbs/ft 3
Weight (cured state) 128 lbs/ft 3
Ideal Slump max 5 5/16”
Working time 10–25 min
Final set 1–3 hrs
pH (wet state) apx. 11
Water damage resistant yes
Shrinkage (ASTMC-426-99) 0.03–0.05 %
Emissions (ISO 16000-10
[indoor air quality part 10])
< 10 μg/(m² h)
Product group: Floor
Date: 05/19/2019
Page: 1(2) CM 780 Fiber Basic 
3.6 qt 44 lb 10–25
min 
1/4”–4” 50–77 °F 
3
min 1–3
hrs 

Combimix datasheet 
Combimix AB • Verkstadsvägen 6 • SE - 746 40 Bålsta • Tel. +46 (0)171-46 65 90 • info@combimix.com
Information contained herein or otherwise administered by Combimix
or its affiliates is based on current and present knowledge of products
when used under normal circumstances and according to Combimix
recommendations. Before using product, user will determine suita-
bility of product for its intended use and assumes all related risks,
responsibility and liability. 
Notice 
Product group: Floor
Date: 05/30/2017
Page: 2(2) CM 780 Fiber Basic 
the directions of flooring manufacturer in regards to maximum allowable moisture content for
floor covering. Substrates should be tested prior to the installation of Combimix product.
Where substrate moisture exceeds the maximum allowed Combimix recommends the use of AC
TECH 2170 moisture migration product. for more information go to: www.actechperforms.com 
Storage time and packaging 
Store in a dry environment, on an unopened plastic-coated pallet, six months from the date of
production. The date of production is printed on the packaging. May be used after 6 months but
properties such as flow rate, hardening and drying times will be extended. CM 780 Fiber Basic
is delivered in 44 lb (20 kg) bags and in big bags. 
Residual products and safety information 
Empty bags can be burned. Any remaining, dry powder that has been stored properly can be
used again. Hardened material should be disposed of as construction waste. Do not wash the
product into the sewage system. The cement in the product has a reduced level of chromate.
Follow regulations in each respective country. 
Health, environment, safety and technical service documents 
For current version of product information, contact Combimix at info@combimix.com
Previously undated and dated issues are no longer valid. For more information contact our sales
organization.
