How to Guide

Mud Bed Mix
Instructions for Mixing
For best results, TEC® Skill Set™ Mud Bed Mix should be installed
in temperatures between 40º-95ºF. Maintain temperature control for
24 hours before, during and 48 hours after installation.
Step 1: TEC® Skill Set™ Mud Bed Mix can be mixed by hand in a
clean wheelbarrow or mortar box, or by machine in a mortar mixer.
Mix each 50 lb. bag with 1.75-2.75 quarts of clean cool water or with
2-3 quarts of TEC® Skill Set™ Latex Mortar Additive for added
performance. For hand mixing, gradually add water (or additive) to
mud bed while mixing with a mortar hoe in a wheelbarrow or mortar
box. For machine mixing, add water (or additive) first to mixer. Mix
to a dry or semi-dry consistency that can be formed by hand into a
ball without crumbling apart. NOTE: Adding too much water or
additive can lead to shrinkage cracks.
Step 2: When bonding mud bed, apply a slurry bond coat, using one
of the following mixes:
 Portland cement mixed with water or additive (1:1 ratio)
 Any TEC® Skill Set™ latex-modified mortar suitable for
your tile application.
Application Instructions
Direct-bond mortar bed:
1. Broom or scrub slurry bond coat into the concrete substrate. It is
critical that the slurry be completely wet (rather than partially dry)
when applying the mud bed mix. Keep a constantly wet slurry on the
floor. Set the screed guides using float strips or mortar screeds to
the necessary floor tolerances.
2. On sloping floors, slope where necessary to the drains. Screed
guides should be tooled to a square-edge right angle.
3. While the slurry is still wet, spread a thin layer of the mud bed mix
onto the floor surface between strips using a straight edge. Work the
mud bed mix with a wood or magnesium float into the slurry bond
coat. Immediately follow with more mud bed mix to the desired
height, compacting and closing up the surface.
4. Finish the surface true and flat to tolerances necessary, typically
1/4" in 10 ft. for tile and stone.
Floating or unbonded mortar bed:
1. Floating screeds are typically used when it is necessary to isolate
a tile assembly from problematic floor conditions using a cleavage
membrane or slip sheet. The TCNA has a variety of application
details covering tile installations over mortar beds incorporating the
use of a cleavage membrane. See the latest TCNA handbook for
more information on floating mortar beds.
2. Apply a cleavage membrane or slip sheet (6 mil polyethylene or
15 lb. roofing felt) to the substrate.
3. Lay out rolled or self-furred sheets of 2" x 2" 16-gauge galvanized
wire mesh throughout installation. Overlap mesh by 2" and connect
using wire ties.
4. Apply mud bed mix into the wire mesh. The mesh must be either
propped up before or during the application, so that the mesh is
approximately in the middle of the mortar bed with at least 5/8" of
mortar thickness covering the wire mesh.
5. Work the mortar mixture with a wood or magnesium float to
compact and close up the surface.
6. Finish the surface true and flat to tolerances necessary, typically
1/4" in 10 ft. for tile and stone.
Expansion and control joints:
 For expansion and control joints, see complete details in
TCNA Handbook Detail EJ171.
 Expansion and control joints placed within the mortar bed
should be carried up through the tile work and left as soft
joints that are filled with an approved elastic material.
Clean Up
Clean tools and tile while the mortar is fresh.
Protection and Curing
 Provide for dry, heated storage on site and deliver
materials at least 24 hours before work begins.
 Protect from rain, snow, freezing and direct solar heat,
which will cause curing and performance deficiencies.
 Because temperature and humidity (during and after
installation of tile) affect the final curing time, allow for
extended periods of cure and protection when jobsite
temperatures drop below 60°F and/or when relative
humidity is higher than 70%.
 Allow mortar to fully cure before installing tile.
 If the installation will be covered with a non-breathable
membrane or if a moisture-sensitive stone is the finish,
allow an extended period of curing before applying the
membrane.
6. WARRANTY
For details about our limited warranties, see your sales associate or
tecskillset.com.
7. TECHNICAL SERVICES
Technical Assistance
Information is available by calling the Technical Service Helpline.
Toll Free: 800-832-9023
Fax: [phone]
Technical and Safety Literature
To acquire technical and safety literature, please visit our website at
tecskillset.com.
©2015 H.B. Fuller Construction Products Inc.
Form # TSSMPP R1014-16
1105 South Frontenac Street
Aurora, IL 60504-6451 U.S.A.
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TEC and Skill Set are trademarks of
H.B. Fuller Construction Products Inc.