Diamond Mountain

Diamond Mountain makes premix concrete and masonry products for Montana, Idaho, and Wyoming contractors. They’re a regional concrete supplier serving the northern Rockies, with a focus on bagged products that can handle the abuse of outdoor storage and still perform when you need them.

Their claim to fame? A waterproof double-bag packaging system that actually works. The inner bag is waterproof, protecting the cement from moisture, which means you can stack these bags outside through a Montana winter and they’ll still be usable come spring. That’s not marketing fluff — that’s solving a real problem for contractors who don’t have unlimited warehouse space.

The Concrete Line: Built for Strength, Not Speed

Diamond Mountain’s concrete products lean heavily toward the stronger end of the spectrum. Their 90 lb premix hits 4500 PSI compressive strength, compared to the typical 3000-4000 PSI you’ll find in standard mixes. They achieve this through larger aggregates — one-inch minus rock instead of the finer materials most brands use.

Product	Weight	Yield	Strength	Water Required
Premix Concrete	90 lbs	0.85 cu ft	4500 PSI	0.8 gallons
Premix Concrete	80 lbs	0.60 cu ft (approx)	4500 PSI	Not specified
Premix Concrete	60 lbs	0.5 cu ft	4850 PSI avg	0.5 gallons

The 90 lb bag is their workhorse. It takes 32 bags to make a cubic yard, and uses ASTM C150 Type I/II GU Portland cement. That’s general-use cement that works in most conditions — nothing fancy, just reliable performance.

Their 60 lb bags actually test stronger on average — 4850 PSI at 4-inch slump. But here’s the thing about concrete strength: anything over 4000 PSI is overkill for most residential work. You’re paying for strength you probably don’t need unless you’re pouring a commercial floor or a heavy-equipment pad.

Specialty Products: When Standard Concrete Won’t Cut It

Diamond Mountain’s 60 lb Topping Premix fills a specific niche — thin concrete applications from 1/2 inch to 2 inches. This isn’t your standard concrete mix. It’s a uniform blend of Portland cement and high-quality commercial sand, designed specifically for resurfacing and repair work.

What makes this product interesting is that it’s manufactured using local Montana raw materials. That matters more than you might think. Local aggregates mean the mix is tuned for local conditions — freeze-thaw cycles, moisture levels, the works.

You’ll use about 0.5 gallons of water per 60 lb bag, and it yields 0.5 cubic feet. The applications are straightforward: fixing scaled concrete, topping old slabs, patching cracks, leveling uneven floors. It’s the product you reach for when full-depth replacement isn’t necessary or practical.

Their masonry products round out the line. The 50 lb Type S Masonry Premix contains 13 lbs of masonry cement and requires 0.45 gallons of water per bag. Type S means structural strength — minimum 1800 PSI. This is what you use for load-bearing walls, not just pointing brick.

Who Should Buy Diamond Mountain

Diamond Mountain acquired by BBB&T in 1985 tells you this isn’t a fly-by-night operation. They’ve been around. Their distribution covers Montana, Idaho, and Wyoming, which means they understand mountain construction challenges.

Buy their products if you need concrete that can sit outside without turning into expensive rock-hard lumps. Buy them if you’re tired of standard 3000 PSI mixes that barely meet code. Buy them if you want masonry products with actual cement content specifications, not vague promises.

Skip them if you’re doing basic residential pours where 3000 PSI is plenty. Skip them if indoor storage isn’t an issue for you. Skip them if you’re price-shopping for the cheapest bag on the shelf — that double-bag system and higher strength cost money.

The bottom line on Diamond Mountain: they make concrete products for contractors who’ve learned the hard way that saving a few bucks per bag isn’t worth it when the concrete fails or the bags turn to stone in storage. Their emphasis on long-term stability, durability, and enhanced strength up to 4500 PSI isn’t just marketing. It’s engineering for real job site conditions.

Frequently Asked Questions

Q: How much water is needed for Diamond Mountain’s 90 lb concrete bag? You’ll need 0.8 gallons of water per 90 lb bag. That’s about 3 quarts if you’re measuring with a bucket. Don’t add extra water to make it easier to work — that kills your strength.

Q: Can Diamond Mountain concrete really be stored outside? Yes, their double-bag system includes a waterproof inner bag that protects the cement. The outer bag takes the abuse while the inner bag keeps moisture out. Stack it on pallets, not directly on the ground, and cover it with a tarp if you’re storing it through winter.

Q: What’s the difference between their regular concrete and topping premix? Regular concrete is for pours over 2 inches thick and contains larger aggregates for structural strength. Topping premix is specifically formulated for thin applications from 1/2 inch to 2 inches and uses only Portland cement and sand — no large rocks that would stick up through a thin layer.

Q: How long before weight can be placed on Diamond Mountain concrete? You’ll get workable strength in 3-7 days, but full strength takes 28 days. For fence posts, you can usually backfill after 24-48 hours. For slabs, wait at least 7 days before driving on them.

Q: Is 4500 PSI concrete worth the extra cost for a residential driveway? Honestly? Probably not. A properly prepared base matters more than jumping from 3000 to 4500 PSI. The higher strength shines for commercial floors, equipment pads, or anywhere you’re dealing with heavy point loads. For a basic driveway with good drainage, save your money.