Trench Drain Specification

[martin888888]

We are planning to construct a 6" NPS storm water trench drain. We call out on the plan "install 6"Wx6"D Trench Drain w/ heavy Duty grating". We are not going to include a detail and just spec it out. Our standard storm spec does not have a section for a trench drain. Would it be appropriate to put verbiage in our spec to require a submittal on the product and simply add "NPS Model #XXXX Trench Drain or approved equal" to the product section? I am fine with them constructing to manufacturers specifications and don't think additional verbiage in the spec is needed.

 

[bridgebuster]

nothing wrong with that

 

[DDBPE]

That works, you may want add the same for the grate, some trench drains have different grate options, unless the one you specify to match only has one type of grate.
When we bid, we would look at the one specified and call our suppliers to see if they have it or can give us the "approved equal".
We bidding one now with similar plan note and spec.

 

[civilman72]

Could be too vague... Trench drains come in all kinds of materials. Do you care if it's PVC, concrete or steel?
Does the grate need to accommodate bicycles and ADA? Do you need a minimum grate opening area for drainage capacity?

"Heavy-duty grating" also seems too vague. It may be better to use specific design load rating (i.e. "HS-20").

 

[RHTPE]

We here at the Forum have no idea of the expected type & volume of traffic.

I think that civilman72 is right, it's too vague and will provide the opportunity for bidders to search for the least expensive option that may not best serve your needs.

Many prefabricated trench drain sections require that the trench be surrounded by 4-6" of concrete to effectively stand up to the beating they will get from traffic.

Is "NPS" an acronym for "Non-point Source" or is it a trade name?


Ralph
Structures Consulting
Northeast USA

 

[Ron]

Specify the material. Trench drains come in everything from PVC to cast iron. Big differences in durability and load resistance.

 

[dik]

I often spec a specific item (one that I've often used) or an appd eq. You can do the same for the grating (Fisher and Ludlow and type). I've had no problem with that and nothing has 'backfired'; it's pretty clear and generally get what was spec'd. If a substitution you have a pretty good chance of comparing 'apples' to 'apples'.

Dik