Primers & DPMs
Everything above the subfloor depends on what goes onto it first. Our range of primers, damp proof membranes and moisture vapour suppressants prepares cementitious, calcium sulphate and timber substrates so that smoothing compounds, adhesives and floorcoverings bond properly and stay bonded.
Not sure whether a subfloor needs a primer, a DPM or a moisture vapour suppressant? It depends on the moisture reading and the substrate. Browse the range below, or speak to our technical team about a specific screed. You may also need a smoothing compound to level the floor before installation.
Our Primer and DPM Range
Marldon MXS120 Universal Subfloor Primer is an acrylic primer for porous substrates including cementitious and calcium sulphate or anhydrite screeds, and for priming timber. It is suitable for use with underfloor heating, and is applied ahead of MXS110 smoothing compound to remove the possibility of pin holes.
Marldon MXS160 Epoxy Primer is a two-part, water-based epoxy primer for porous substrates such as concrete, cement and polymer modified screeds, and for brick and blockwork. It is also developed as a breathable sealer for calcium sulphate and anhydrite screeds.
Marldon MXS170 Textured Primer is a ready to use, rapid drying, adhesion promoting primer for both absorbent and non-absorbent surfaces, including existing ceramic and vinyl flooring, asphalt, bitumen and epoxy DPMs. It leaves a textured surface that gives smoothing compounds and screeds an excellent key.
Marldon MXS140 Rapid DPM is a solvent-free, two-part epoxy damp proof membrane developed to suppress residual moisture in concrete and sand and cement subfloors in a single coat, and is suitable for use with underfloor heating.
Marldon MXS150 Rapid MVS is a single part, solvent-free polyurethane moisture vapour suppressant that can also be used as a single coat primer. It is designed for use beneath Marldon smoothing compounds and adhesives, and is suitable for underfloor heating.
Marldon M1-F Bitumen Paper creates a water-resistant barrier where damp is present in a timber subfloor, preventing moisture being absorbed into the flooring above.
Frequently Asked Questions
Do I need a primer, a DPM or a moisture vapour suppressant?
It depends on the moisture in the subfloor, which should be tested to British Standards with a properly calibrated and insulated hygrometer. A primer improves adhesion and controls suction on a subfloor that is already dry. A damp proof membrane such as MXS140 suppresses residual moisture in concrete and sand and cement subfloors. A moisture vapour suppressant such as MXS150 does a comparable job as a single part, solvent-free system. If you are unsure, speak to the Marldon technical team before specifying.
Can subfloor primers and DPMs be used over underfloor heating?
MXS120, MXS140, MXS150, MXS160 and MXS170 are all suitable for use with underfloor heating systems. Underfloor heating should be switched off 48 hours before moisture testing is carried out, so that the reading is accurate.
Which primer should I use on a calcium sulphate or anhydrite screed?
MXS120 Universal Subfloor Primer is suitable for calcium sulphate and anhydrite screeds, and MXS160 Epoxy Primer is specifically developed as a breathable sealer for them. If you are applying a cementitious smoothing compound over a calcium sulphate substrate, contact the Marldon technical department first.
Do I need to prime before using a smoothing compound?
Priming first controls suction and helps the compound flow correctly. MXS120 is applied ahead of MXS110 smoothing compound to remove the possibility of pin holes. On non-absorbent surfaces such as existing ceramic or vinyl flooring, MXS170 Textured Primer provides the key instead.