Diamond Mountain 50 Lbs. Masonry Premix

Diamond Mountain’s 50-pound masonry premix achieves 4,850 psi average strength at a 4-inch slump — significantly exceeding typical Type S mortar requirements. This pre-weighed formula includes 13 pounds of masonry cement mixed with mason sand, yielding approximately 0.5 cubic feet of mixed material per bag when combined with 0.45 gallons of water.

The double-bagging system sets this product apart. A waterproof inner bag protects the cement while a tough outer poly bag handles jobsite abuse. This packaging allows outdoor storage in any weather condition without deterioration of the cement — a critical advantage for Montana contractors who can’t always store materials indoors during the building season.

Performance and Application

Type S classification means this mortar works for structural masonry above or below grade. Workable strength develops in 3-7 days after placement, reaching full strength at 28 days. Applications include bonding brick or stone to existing concrete surfaces, structural masonry work, and general masonry projects where Type S mortar strength is required.

The strength numbers matter. At 4,850 psi average strength, this premix delivers nearly double the minimum 2,500 psi typically required for Type S mortar. Larger aggregates provide a double-strength effect and reduce cracking — particularly valuable in Montana’s freeze-thaw environment where thermal cycling punishes weak mortar joints.

Technical Specifications

Specification	Value
Weight per bag	50 lbs (22.7 kg)
Packaging	48 bags per pallet
Water requirement	0.45 gallons per bag
Yield per bag	Approximately 0.5 cubic feet
Compressive strength (average)	4,850 psi at 4-inch slump
Workable strength period	3-7 days after placement
Full strength period	28 days

Installation and Mixing

Dry mix the bag contents before adding water to ensure the cement and sand are evenly distributed. Mix with exactly 0.45 gallons of water per 50 lb bag. The product is designed for performance at a 4-inch slump.

The precise pre-weighing eliminates field mixing errors. Standard mortars often require manual mixing of sand and cement in the field, leading to inconsistent ratios. Diamond Mountain is precisely pre-weighed and pre-mixed. This consistency matters when structural integrity depends on achieving specified strength.

The Montana Advantage

Manufactured in Frenchtown, MT by Diamond Mountain Products (a subsidiary of Bozeman Brick Block and Tile), this product understands Montana jobsite realities. The double-bag system allows for outdoor storage, whereas standard paper-bagged mortar must be kept dry and indoors.

It is widely used by masonry professionals in Montana for its reliability and outdoor storage capabilities. The waterproof packaging solves a real problem — contractors can leave pallets on-site without worrying about overnight rain ruining their mortar supply.

FAQs

Q: Can this mortar really be stored outside?

Yes. The double-bagging system uses a tough outer poly bag and a waterproof inner bag to protect the product. It can be stored outdoors in any weather condition without deterioration of the cement.

Q: How much water do I need per bag?

Add exactly 0.45 gallons of water per 50 lb bag. Too much water weakens the mix; too little makes it unworkable.

Q: What’s the coverage per bag?

Each bag yields approximately 0.5 cubic feet of mixed material. Plan accordingly based on joint thickness and brick/stone size.

Q: How does this compare to mixing my own mortar?

Standard mortars require manual field mixing of sand and cement, leading to inconsistent ratios. Diamond Mountain comes precisely pre-weighed and pre-mixed. The cement is precisely weighed and placed in its own waterproof bag to ensure consistent strength and quality.