I have two installed inspection chambers of 600mm diameter both of which are to be reduced in height following a landscaping design change. As part of that change we're also looking to reduce the drain cover size to 320 or 350mm still allowing access for any required clearing.

 

I can find plenty of access restriction or shaft reducing caps, but none of these look like they are designed to allow a change from one riser diameter to another e.g 600mm to 320/350mm (hope the next diagram explains it a bit more)

 

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Anyone know of a suitable "riser diameter changer" product?

4 hours ago, BotusBuild said:

I have two installed inspection chambers of 600mm diameter both of which are to be reduced in height following a landscaping design change. As part of that change we're also looking to reduce the drain cover size to 320 or 350mm still allowing access for any required clearing.

 

I can find plenty of access restriction or shaft reducing caps, but none of these look like they are designed to allow a change from one riser diameter to another e.g 600mm to 320/350mm (hope the next diagram explains it a bit more)

 

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Anyone know of a suitable "riser diameter changer" product?

Price is horrific, but shop around. 
 

https://www.drainagesuperstore.co.uk/product/axedo-600mm-to-350mm-inspection-chamber-restrictor-ring.html?clickref=1100lDp3y34Q&reqid=73079187&affid=1694&app_clickref=1100lDp3y34Q

Yeah, seen those, but it seems there is no ability to then add 320mm or 350mm riser on top of it. Something like this:

 

https://www.tradepipes.co.uk/320mm-diameter-chamber-riser-135mm-high?source=googlebase&msclkid=d5cfa3ce6b6b1d0776b3c94ae6007d73&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping Campaign&utm_term=4577816667752085&utm_content=Underground Drainage

1 hour ago, BotusBuild said:

Yeah, seen those, but it seems there is no ability to then add 320mm or 350mm riser on top of it. Something like this:

 

https://www.tradepipes.co.uk/320mm-diameter-chamber-riser-135mm-high?source=googlebase&msclkid=d5cfa3ce6b6b1d0776b3c94ae6007d73&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping Campaign&utm_term=4577816667752085&utm_content=Underground Drainage

There must be, as it would need to take a modular access cover. 
 

Ring them on Tuesday and ask for a solution. 

14 hours ago, BotusBuild said:

it seems there is no ability to then add 320mm or 350mm riser on top of it.

Why not use a 600mm riser before it?

Mike, the 600mm Risers are already there 😀 Thats what I want to reduce from

14 hours ago, Nickfromwales said:

Ring them on Tuesday and ask for a solution. 

Talk to someone. That's a radical solution. Hope I'm not met by a bot!! 😉

 

 

24 minutes ago, BotusBuild said:

Mike, the 600mm Risers are already there 😀 Thats what I want to reduce from

You appear to want to do the left illustration below. I'm suggesting the one on the right. But maybe you're trying to do something else.

 

@Mike, either would do, as long as there is some reduced diameter riser before the cover goes on

This might do the job but there is an ambiguous picture in the listing. The phone call is needed to clarify whether it will work before forking out a sh1t load of wonga

 

https://www.drainagesuperstore.co.uk/product/accesso-ic160-600mm-reduction-cap-350mm-circular-access.html