[Published: 19 October 2026 | Last updated: 19 October 2026] | 6 min read
TL;DR
- Most cast iron sewer drain covers (manhole covers) weigh between 80 and 300 pounds, and a standard 24-inch municipal cover weighs about 100 to 150 pounds (Neenah Foundry, accessed October 2026). neenahfoundry
- The frame adds weight. A cast iron frame adds another 75 to 250 pounds (Neenah Foundry, accessed October 2026). neenahfoundry
- Storm drain grates and curb inlet castings are heavier than most sewer lids. Municipal specifications list curb inlet grates at 410 to 500 pounds (City of Ann Arbor, accessed October 2026). a2gov
- Small utility covers, such as lamphole and oil line covers, weigh as little as 22 to 85 pounds (Seattle Parks and Recreation, accessed October 2026).
- Check the casting number on the cover and look up the manufacturer’s spec sheet for an exact weight.
How Much Does a Sewer Drain Cover Weigh?
A sewer drain cover weighs between 80 and 300 pounds in most cases. Neenah Foundry puts a standard 24-inch municipal cover at roughly 100 to 150 pounds (Neenah Foundry, accessed October 2026). neenahfoundry
This article uses “sewer drain cover” to mean the round lid over a sewer access shaft. It is also called a manhole cover or sewer lid. A “storm drain grate” is the slotted metal top over a street inlet, and it is a separate casting with its own weights.
The range is wide because covers are built for different jobs. A lid on a footpath needs less metal than one in a highway lane.
What Determines Sewer Drain Cover Weight?
Four factors set the weight: material, diameter and thickness, load rating, and design features.
- Material: cast iron, ductile iron, and composite covers weigh different amounts at the same size. Composite covers are the lightest.
- Diameter and thickness: a wider, thicker cover uses more metal, so it weighs more.
- Load rating: the heavier the required rating, the heavier the cover (Neenah Foundry, accessed October 2026). neenahfoundry
- Design features: vented covers weigh slightly less than solid ones, and watertight or gasketed covers weigh slightly more (Neenah Foundry, accessed October 2026). neenahfoundry
Sewer Drain Cover Weight Chart by Casting Type
Weights depend on the manufacturer and model, so treat the figures below as published examples from municipal specifications and supplier listings.
| Casting type | Listed weight | Source |
|---|---|---|
| Oil line frame and cover (EJ 3670) | 22 lb | Seattle Parks and Recreation, accessed 2026 |
| Lamphole frame and cover (EJ 3669) | 25 lb | Seattle Parks and Recreation, accessed 2026 |
| Lamphole frame and cover (EJ 3660) | 85 lb | Seattle Parks and Recreation, accessed 2026 |
| Monument box (EJ 8360) | 100 lb | City of Ann Arbor, accessed 2026 |
| Standard 24-inch municipal cover | 100-150 lb | Neenah Foundry, accessed 2026 |
| Manhole cover (Neenah R-1642, EJ 1040 Type A) | 380-400 lb | City of Ann Arbor, accessed 2026 |
| Yard drain grate | 285-400 lb | City of Ann Arbor, accessed 2026 |
| Curb inlet grate | 410-500 lb | City of Ann Arbor, accessed 2026 |
| Hoodback inlet frame and grate (EJ 7030), total | 513 lb | City of North Augusta, 2023 |
The jump between a 100 to 150 pound standard cover and a 380 to 400 pound municipal cover comes mostly from diameter and the load rating the city requires.
Do Cast Iron, Ductile Iron, and Composite Covers Weigh the Same?
No. Cast iron and ductile iron covers are the heaviest, and composite covers are the lightest.
Ductile iron (a stronger, less brittle form of cast iron) can be cast thinner than gray iron for the same strength rating. That can make a ductile iron cover lighter than a gray iron cover of the same diameter.
Composite covers are made from fiberglass-reinforced polymer. They can still meet highway standards. Fibrelite’s 30-inch and 36-inch composite covers passed the AASHTO H20 test, which applies a 40,000-pound proof load (CompositesWorld, accessed October 2026). Published weights for composite covers vary by model, so check the manufacturer’s data sheet. manufacturing
Why Are Sewer Drain Covers So Heavy?
Covers are heavy because they must carry vehicle traffic and stay in place. A heavy cover resists being knocked loose, lifted by pressure from below, or taken by thieves.
The load requirement is specific. East Jordan Iron Works lists its heavy-duty covers as proof tested to a minimum of 40,000 pounds under AASHTO M306 (Ferguson, accessed October 2026). AASHTO M306 is the American Association of State Highway and Transportation Officials standard for drainage castings. ferguson
Shape matters too. Most covers are round because a round cover cannot fall through a round opening, whichever way it is turned (Neenah Foundry, accessed October 2026). neenahfoundry
How Heavy Is the Frame, and What Is the Total Weight?
The frame (also called the ring or casting) sits in the pavement and holds the cover. Add its weight to the cover weight to get the full assembly.
A cast iron frame adds 75 to 250 pounds (Neenah Foundry, accessed October 2026). Frames alone can be much heavier for storm inlets. The East Jordan 5130Z catch basin frame has a shipping weight of 294 pounds (Kuhlman, accessed October 2026), and the smaller square 5250Z frame ships at 139 pounds (Kuhlman, accessed October 2026). how much does a manhole cover weigh and why does it matter +2
Complete inlet assemblies add up fast. The East Jordan 7030 hoodback inlet is listed at 328 pounds for the frame and back plus 185 pounds for the grate, 513 pounds in total (City of North Augusta, 2023). northaugustasc
How Do You Find the Exact Weight of a Specific Cover?
Read the markings on the cover, then look up the model.
- Find the casting number or manufacturer name cast into the surface. Common names are East Jordan Iron Works and Neenah Foundry.
- Measure the cover diameter and note any city or utility name on it.
- Search the casting number on the manufacturer’s site or a supplier listing, which usually shows weight.
- Check your city’s standard details. Many public works departments publish approved casting weights, as in the Ann Arbor and North Augusta documents cited above.
- Weigh a removed cover on a rated scale if no marking is readable.
How Do You Lift a Sewer Drain Cover Safely?
Use a lifting tool, never your hands alone. A 100 to 150 pound cover is too heavy to lift safely by hand, and many are heavier.
A wheeled cover dolly rolls the cover clear so nobody has to hold it (Neenah Foundry, accessed October 2026). Pickbars and J-hooks fit the pickholes cast into most covers. Utility workers should follow their employer’s confined-space and traffic-control procedures before opening any sewer access point. neenahfoundry
Homeowners should not open municipal sewer covers. Call the local utility or a licensed plumber.
Common Mistakes When Estimating Cover Weight
- Weighing only the lid. The frame can add 75 to 250 pounds, so the assembly weighs far more than the cover alone.
- Mixing up covers and grates. A curb inlet grate at 410 to 500 pounds is much heavier than a typical 100 to 150 pound sewer lid.
- Assuming all covers are cast iron. Composite and ductile iron covers of the same diameter can weigh noticeably less.
- Trusting a generic average. Published weights are per model, so use the spec sheet for the exact casting.
Frequently Asked Questions About Sewer Drain Cover Weight
How much does a standard sewer drain cover weigh?
A standard 24-inch municipal cover weighs about 100 to 150 pounds. Most cast iron covers fall between 80 and 300 pounds (Neenah Foundry, accessed October 2026).
How much does a storm drain grate weigh?
Storm drain grates weigh 265 to 500 pounds in municipal specifications. Gutter inlet grates run lighter, and curb inlet grates run heaviest (City of Ann Arbor, accessed October 2026).
Why are manhole covers so heavy?
They are built to carry road traffic and resist displacement. East Jordan lists its heavy-duty covers as proof tested to 40,000 pounds (Ferguson, accessed October 2026).
How much does a manhole frame weigh?
A cast iron frame adds 75 to 250 pounds to the cover weight (Neenah Foundry, accessed October 2026). Storm inlet frames can weigh more, such as the 294-pound East Jordan 5130Z (Kuhlman, accessed October 2026).
Are there lighter alternatives to cast iron covers?
Yes. Composite covers are lighter and can pass highway load tests. Fibrelite’s composite covers passed the AASHTO H20 40,000-pound proof load (CompositesWorld, accessed October 2026).
What is the lightest type of sewer cover?
Small utility castings are the lightest. East Jordan’s 3670 oil line cover weighs 22 pounds, and the 3669 lamphole cover weighs 25 pounds (Seattle Parks and Recreation, accessed October 2026).
Key Takeaways
- Expect 100 to 150 pounds for a standard 24-inch sewer drain cover and up to 300 pounds or more for larger or heavier-rated ones.
- Add the frame weight, which can be 75 to 250 pounds, when estimating the full assembly.
- Grates over storm inlets are the heaviest castings, at 265 to 500 pounds in city specs.
- Look up the casting number for an exact weight, and use proper lifting tools.
References
- Neenah Foundry. “How Much Does a Manhole Cover Weigh, and Why Does It Matter?” https://neenahfoundry.com/blog/how-much-does-a-manhole-cover-weigh-and-why-does-it-matter/
- City of Ann Arbor. Standard casting specification sheet (sd-gu-5). https://a2gov.org/media/y5jbjojv/sd-gu-5-model.pdf
- CompositesWorld. “Composite manhole covers pass load tests.” https://www.compositesworld.com/news/composite-manhole-covers-pass-load-tests
Leave a Reply