Lifting Internal manhole cover

[Jonm]

My daughter/son in law wish to tile their conservatory. Tiles bought, tiler coming Friday. Lifted the carpet to find a manhole cover on the floor, see photo. I would like to lift the cover to assess what to do.

Dimensions 530 by 680. There are four screws and no lifting eyes. The screws turn but as yet not managed to completely unscrew them. I am not sure if:
1. they operate lugs which go in to the side of the frame, in which case they will not come out so how to lift the frame.
2. they are threaded in to the frame, in which case it would not be possible to screw in lifting eyes.
3. they are threaded in to the frame and are blanking screws so a lifting eye could be fitted, in which case the cover is not screwed down.
4. There is a larger threaded hole in the frame and smaller bolt threaded in to the frame. So a larger lifting eye can be fitted.

I have looked online and found similar manholes but there is no detail of the fixings.

Does anyone have experience of these? If so I would appreciate some comments.

 

[Seascaper]

My daughter/son in law wish to tile their conservatory. Tiles bought, tiler coming Friday. Lifted the carpet to find a manhole cover on the floor, see photo. I would like to lift the cover to assess what to do.

Dimensions 530 by 680. There are four screws and no lifting eyes. The screws turn but as yet not managed to completely unscrew them. I am not sure if:
1. they operate lugs which go in to the side of the frame, in which case they will not come out so how to lift the frame.
2. they are threaded in to the frame, in which case it would not be possible to screw in lifting eyes.
3. they are threaded in to the frame and are blanking screws so a lifting eye could be fitted, in which case the cover is not screwed down.
4. There is a larger threaded hole in the frame and smaller bolt threaded in to the frame. So a larger lifting eye can be fitted.

I have looked online and found similar manholes but there is no detail of the fixings.

Does anyone have experience of these? If so I would appreciate some comments.View attachment 160018

Hello, there is a special T shaped key that comes with this sealed manhole. These manholes are often used to replace traditional outdoor manholes when built over such as a conservatory or kitchen extension. The new type have rubber seals which are screwed down in place. The T shaped key bottom part has an Allen key end, about 6/7mm then a thread so you undo the bolts and then use the thread of the key into the manhole thread and lift. Here is photo of the key. My similar manhole has the following details on it. Manufacturers are ACO, www.aco.co.uk
You would probably get by with using the Allen key to undo the stainless bolt and the use a threaded bolt about M8 size, screw into thread and attach a pair of mole grip to bolt head for lifting.
This is the kit with the bolts and lifting key that comes with the new installation.
Best regards.

 

[Seascaper]

Hello
The dilemma you will be faced with is how to tile. The manhole recess has been filled with concrete to match surrounding floor. One can tile and cut to manhole edge and drill holes through tiles andfinish with plastic plugs.
These installations are common nowadays so if you are using a professional tiler they should know what to do. I could be more effort and expense to completely cover over and provide a rodding point outside. One can sometimes get by with a small circular manhole sited outside under the gravel. There might even be one, if you walk around the gravel striking the ground with a metal pole you might discover another access point in which case the internal cover could be covered over.
Regards

 

[Adam W.]

.

 

[ChaiLatte]

The screws turn but as yet not managed to completely unscrew them

The description above covers how they are built and how they are supposed to be lifted. His suggestion of an alternative key is sound.

You are left with the issue of removing the screws. In principle, they should come out completely.

On the ones I have seen, the female thread in the frame is provided by means of a nutsert. If the screw has been inserted cross-threaded or has corroded into the nutsert, the nutsert itself can spin in the frame, and you will never undo the screws. The only way then to remove the cover is to drill off the screw heads, itself not an easy task. That will allow the cover to be lifted. You are then left with another problem of how to re-secure the cover...

 

[TRITON]

Screws/bolts might be captive, as in they aren't meant to come fully out.

 

[Jonm]

Well thank you for all this useful information. I have now managed to remove the bolts, they came out completely. They are slotted head. I am going to look again at how to lift it this evening.

 

[Jonm]

Hello, there is a special T shaped key that comes with this sealed manhole. These manholes are often used to replace traditional outdoor manholes when built over such as a conservatory or kitchen extension. The new type have rubber seals which are screwed down in place. The T shaped key bottom part has an Allen key end, about 6/7mm then a thread so you undo the bolts and then use the thread of the key into the manhole thread and lift. Here is photo of the key. My similar manhole has the following details on it. Manufacturers are ACO, www.aco.co.uk
You would probably get by with using the Allen key to undo the stainless bolt and the use a threaded bolt about M8 size, screw into thread and attach a pair of mole grip to bolt head for lifting.
This is the kit with the bolts and lifting key that comes with the new installation.
Best regards.
View attachment 160059

Thank you for spending the time to take a photo. It is very helpful.

 

[Jonm]

I have had another go at lifting the cover. Holding down screws are 8mm, the cover is threaded to take 10mm. Problem is that the threaded part of the cover is thin metal so three of the four have stripped out, despite me being careful. I can see how I could get a good fixing for lifting but there are some concrete fines between cover and frame which is rock solid so hard to get out.

Given that it needs a new cover and frame for the tiles and the frame goes under the bottom rail of the conservatory, I will probably go for cutting the concrete floor around the cover and remove the concrete, then cut the frame and get the cover out.

What a pain.

 

[Alli]

At work we have a similar type manhole cover. We have found the only way to lift it, is by using a pry bar between the metal edges/gap to lever up a side. Once the 'seal' gets broken we have half a chance to lift it out. The best tool we have found to work the best is in the following link. There are cheaper models but this was the first pic I could find.

https://www.toolstation.com/milwauk...0TclrNkQjZOpRUKoA24aAsn-EALw_wcB&gclsrc=aw.ds

 

[Alli]

We also have these bars, which I am sure are homemade but do help lifting the cover up and out the hole.

 

[eribaMotters]

My daughter/son in law wish to tile their conservatory. Tiles bought, tiler coming Friday. Lifted the carpet to find a manhole cover on the floor, see photo. I would like to lift the cover to assess what to do.

Dimensions 530 by 680. There are four screws and no lifting eyes. The screws turn but as yet not managed to completely unscrew them. I am not sure if:
1. they operate lugs which go in to the side of the frame, in which case they will not come out so how to lift the frame.
2. they are threaded in to the frame, in which case it would not be possible to screw in lifting eyes.
3. they are threaded in to the frame and are blanking screws so a lifting eye could be fitted, in which case the cover is not screwed down.
4. There is a larger threaded hole in the frame and smaller bolt threaded in to the frame. So a larger lifting eye can be fitted.

I have looked online and found similar manholes but there is no detail of the fixings.

Does anyone have experience of these? If so I would appreciate some comments.View attachment 160018

Do you need to disturb the manhole cover? If you can gain access to the drains from either side then I would simply tile your floor and not worry, and I'm known for worrying.

Colin