Masons Mortar Ltd DPM Dry Placement Mortars
Dry placement mortars with rapid setting for damp, wet, rapidly submerged or exposed rough racked footpaths.
| Compressive strength 72h | 2 N/mm2 | BS998.2 | ||
| 7 days | 4.5 N/mm2 | BS998.2 | ||
| 28 days | 8N/mm2 | BS998.2 | ||
| Capillary 28 days | 0.45 g.min | BS1015 | ||
| Flexural Strength 28 days | 2 N/mm2 | BS1015 | ||
| Modulus of Elasticity 28 days | 9000 – 11000 MPa | BS1015 | ||
| Vapour permeability | (0.65g x m2 x h x mmHg) | EN 1015 |
Offering very low capillarity, good vapour permeability with an exceptionally rapid initial rate of setting, Masons Mortar Ltd DPM mortars are specifically designed for high foot traffic areas where joints are large and the mortar is acting as a unifying surface finish between often irregular masonry units or where unpredictable intermittent inundation or tidal submersion is certain. The mortar is applied as a dry brushed joint filler and hydrated after placing.
Consisting of Eminently hydraulic lime, natural cement, well-graded concrete sand with fillers and additions to improve hydration, the materials offer a simple economic solution for deep tamped joints in an horizontal plane in wet or soon to be wet areas.
Supplied as a ready mixed mortar to be used dry as a dry placement brushed in joint filler between masonry units with deep (40mm or more) visible deep joints at least 10mm not exceeding 100mm wide.
Clean all surfaces that are to come into contact with the mortar with a power washer, biocide or other methods with approved equipment. Mortar contact surfaces must be clean to ensure a proper bond between the new mortar and the masonry units.
Low or none permeable masonry units such as basalt, whin or dense granite, are usually sufficiently robust to be power washed with a high pressure nozzle in close proximity to the masonry, power washing may also be consider as a means to remove deleterious or redundant mortar between joints and can in the hands of experience operatives be the means to create relatively regular depth joints.
In costal, river and spillway areas, biocide removal of the joint interfaces is very important. (Consult with the suppliers of Biocide treatments whether there are any environmental risks from their use in watercourses and waterways)
Slabs, setts or cobbled surfaces may be high suction, to avoid staining and after cleaning, the upper facing surfaces of the slabs etc., may be treated with our anti surface staining product – No-Stain a clear liquid applied by fine mist sprayer after cleaning and biocide treatment over the porous surfaces ahead of the application of Masons Mortar Ltd DPM.
If the masonry slabs or setts to be pointed are laid on damp or wet (not saturated) soils or sub bases, no pre-wetting of the joint base is required.
If the base of the joints are touch dry, use a hose with a fine nozzle to wet the bottom of the joints, allow this to be absorbed leaving the joint base damp and ready to receive the dry mixed mortar.
Ponding water is to be avoided. If permanently wet (ponding) conditions exist consult our technical department [email protected]
Allow any water over spill on to the slabs or setts to dry, an air line may be used to remove any surface water before spreading the dry mortar mix if time is limited, ensure the surface of the slabs are dry to avoid un-necessary clean up.
A two-person team is best to carry out the work. After laying the bags of ready mixed mortar out on to dry surfaces, cut the bags open and discharge the contents directly on to the area to be pointed.
Using a wide soft brush, move the mortar back and forth over open joints until the joints are full continue the process until all the joints are full. Brush across the joints avoid brushing with the joints.
Follow up immediately with a long handled tamping tool to compact the joints – long handles floor scrapers are ideal for tighter joints and varying width of joint tampers should be used to ensure the maximum compaction of dry product into each joint.
Add more DPM to any areas where the joint compaction leaves the mortar recessed; ensure all mortar is at least flush with the surrounding masonry.
Brush the slabs, setts completely clean.
With a back pack sprayer of a fine mist from a garden hoe, gently but liberally dampen the joints, start at the highest point of the area and work downward, do not over wet the mortar, allow it to absorb water often and in small amounts to achieve the best level for full hydration.
Pass over an area of sufficient size to allow the joints to be dampened at least 2-3 times in any 5-minute spell. If the joints are very deep – in excess of 50mm repeat at least 4 times in the first 10 minutes.
Continue watering the joints for at least 3 more passes and allow at least 2 hours but not more than 3 hours to pass before applying water liberally with a rose head sprinkler to the entire area and minor inundation of the joints – check as the wetting process is being carried out whether joints are still absorbing water readily, when the joint ceases to absorb water move on or stop the wetting process.
Masonry that will not be inundated by rising tidal flow should be covered with damp hessian over night. Wave scour (crashing, rolling breakers) should be avoided for at least 24 hours. If direct wave action is anticipated, consult our technical department [email protected]
All work must be protected from Frost for 24 hours.
Masons Mortar Ltd offer a range of specialist mortars and grouts for wet work areas, some materials in specific circumstances may be used where standing water exists and cannot readily be removed. We also have materials and equipment that can be used for wet work where water is dripping from arch barrels, such as the underside of bridges and the like.
Feel free to contact us and discuss any issues relating to mortars and their placement
Our [email protected] help line I accessible directly or through our enquiry section on our web site masonsmortar.co.uk.