How do I know what size manhole cover I need?
Manhole cover dimensions are determined by the internal size of the access chamber, referred to as the clear opening, this is the hole through which a person or equipment can pass. To obtain an accurate clear opening, any existing cover or coverings must first be removed. The clear opening is critical as in many cases parts of the cover / frame hang within this void.
I can only take measurements of the cover & frame at surface level, can you work from these sizes?
We can produce a cover and frame to match these dimensions but internal frame opening may not align with the chamber. This is generally not an issue with side lid units but can cause problems with twin and multiple covers where support beams are incorporated, the beams must fit accurately between the chamber walls.
I have a chamber with a clear opening that is different from any shown on your web site what do I do?
Non-standard sizes are available on request, contact our sales department for a quotation.
Can I set two manhole covers side by side to cover a larger clear opening?
Not without installing a central support, all four sides of the cover and frame need to be supported to achieve the required loading. We can supply a single piece frame with multiple covers and a removable centre support bar for these situations.
I am installing a recessed cover & frame in a swimming pool area, are there any special requirements?
Due to the corrosive nature of swimming pool environments we would only recommend the use of fully stainless steel grade 316 products.
Can you supply a recessed cover and frame with a grade 316 stainless visible edge?
If the environment requires the use of grade 316 stainless steel for corrosion protection an edged cover & frame is not suitable. Stainless steel edges on products are for aesthetic purposes only, the base material (galvanised steel) is still susceptible to atmospheric conditions.
What is the definition of a slow moving wheel load (SMWL)?
Slow moving wheel loads are deemed to be speeds no greater than 20 mph in low intensity trafficked areas.