DOWSIL 795 Silicone Building Sealant is a one-part neutral-cure silicone certified to ASTM C1184 for structural glazing and ASTM C920 Class 50 for weatherproofing. It is the product you order when the specification names those standards by title and a submittal has to be approved by someone who will read it.
Quick answers
What standards does DOWSIL 795 meet?
ASTM C1184 (structural silicone sealant) and ASTM C920 Class 50 (elastomeric joint sealant), per Dow's published technical data sheet. That combination is why it appears in so many curtain-wall specifications by name.
Can it be used for both structural and weatherproofing?
Yes — that is unusual and it is the point. One product covers the structural bond and the weather seal, which means one submittal and one material on site instead of two.
How is it sold?
We sell it by the case of 16 sausages, 20 fl oz each. Case price $239.84, dropping to $207.84 from 20 cases — $12.99 per sausage at volume. How volume pricing works.
Why is it more expensive than the other sealants here?
Because the certification is the product. Our Seimeda and Silande grades perform, and we sell plenty of them — but they are tested to GB 16776-2005 and GB/T 13477, which is not ASTM certification and not a US code approval. Where a drawing names ASTM, the certification is what you are buying.
When you have no choice
Four situations where substituting is not a saving:
- The specification names ASTM C1184 or C920 by title. A submittal offering a product that does not carry the named standard gets rejected, and you lose the week.
- Four-sided or hidden-frame structural glazing. The silicone is the attachment — there is no cap and no pressure plate doing the holding. Bite and glueline are calculated by the project engineer, not chosen on site.
- The project requires the manufacturer's structural warranty. That is issued against the manufacturer's own product and its own adhesion testing, not against an equivalent.
- Anything that will be examined after a failure. If a facade is ever investigated, the question is what was specified and what went on. Those two answers should match.
When you do not need it
Plenty of real work does not call for ASTM by name. A perimeter joint around a storefront door, a cap bead over a captured system, panel-to-panel weatherproofing — these need a good neutral-cure weatherproofing sealant with the right movement class, and Silande MF898 does that at a fraction of the cost. We would rather sell you the right thing than the expensive thing.
Which grade your joint actually needs.
How it compares to what else is on this site
| Product | Grade | Standards | Case | From 20 cases |
|---|---|---|---|---|
| Seimeda neutral cure | General weatherproofing | GB 16776-2005, GB/T 13477 | 20 sausages | $100.00 |
| Silande MF898 | Architectural weatherproofing | GB/T 22083, ASTM C920 (100/50) per label | 20 sausages | $140.00 |
| Silande MF899 | Structural | GB 16776, ASTM C920 per label | 20 sausages | $180.00 |
| DOWSIL 795 | Structural + weatherproofing | ASTM C1184, ASTM C920 Class 50 | 16 sausages | $207.84 |
A note on that table, because it matters: the Silande standards are read off the manufacturer's own product labels. That is a manufacturer declaration, not a third-party certificate, and we will not describe it as one. DOWSIL 795 is the line where the certification is independent and named.
Using it
It loads in the same 20 fl oz sausage gun as everything else we sell — and being a high-viscosity structural grade, it is the clearest case for an 18:1 gun rather than 12:1. In cold weather bring the sausages up to room temperature overnight before you try to tool it.
Test adhesion on your actual substrate before committing a facade to anything, this product included. Coatings vary between batches. Ask us for a sample.
Getting it
Sold by the case of 16, off our own floor in Jersey City, with free delivery across all five boroughs of New York City. Colour availability moves — the product page shows what is on the floor today, and anything showing as out of stock we can order in. Tell us the colour and the quantity and we will give you a date before you commit.