The Brew Cabin

You could bed the blocks around the drain on mortar, but it's not essential. However, you need to get that drain to the correct level first, ie before laying the blocks around it, and just how that's done depends on the type of drain.

Can you describe it or send me a picture?

The drain is approx 400 mm diameter with a black lid on, sent you some pictures today.

Here's the image....


....that's an Inspection Chamber (IC ) and the lid, which is Ductile Iron, sits inside a frame which, in turn sits atop the chamber sections. There's an illustration of this type of IC on the Manholes page.

You need to lift off the cover and frame and then re-set them on a bed of mortar or bricks and mortar, and then tap down to the correct level.
With this drive being on a slope, and you being an amateur, I reckon the easiest way would be for you to pave all around the IC and then set the cover to a level of approximately 8-10mm below the level of the uncompacted paving. This will enable you to get the 'front' end and the 'back' end set to level more accurately than relying on using string lines or straightedges from the existing kerbs.

By how much do you reckon you'll need to lift the cover and frame? Up to 25mm can be done on a simple bed of mortar, but anything more than that will require either slate, broken flags or brickwork to help carry the load.

You also need to think about the detailing around the cover once it's set to the correct level. Have you looked at the Detailing page? That's gives an illustration of the various ways in which you can detail the paving around an IC cover such as this.


Progress to date....

From the manhole page the lid and the frame should come off:

Should I set this to my FPL on a bed of mortar and/or slate then detail the drain during paving then joint ?

Set the drain and detail on a bed of mortar and/or slate before I pave ?

What about when I compact the blocks after will this disturb the mortar on the drain either way ?

I reckon you should lay as much of the paving as is poss, to withing 300mm or so of the IC cover, but don't compact. Then, set the frame and the surround detail blocks on a bed of mortar/concrete, tapping down to finished level. Leave it for 24 hours, then piece-in and you can compact with the wacker plate.

Take it easy around the cover - you can run the plate right up to the detailing, but try not to run over the cover at this stage as it might just rattle loose the bedding mortar.

All edgngs now done ready for the blocks.

Can I block in the rain or damp conditions ?

I have around 2" of sand for about 39 sqm required for the blocks. How much should I order ?

Which is the better tool to use for cutting the blocks, I am using driveline 50. splitter or saw ?

The only weather that stops block laying is torrebntial rain or hard frost/snow. A bit of damp or drizzle is nowt to worry about - if it was, we'd never get any paving laid in this country! ;)

39m2 - you'll need around 4 Tonnes of the grit sand, and then around 5 x 40kg bags of the jointing sand for when you've done.

A splitter is better for concrete blocks, but many diy'ers seem to prefer a cut-off saw, even though it is incredibly dusty, it's noisy, more expensive, more back-breaking and, 12 months down the line, you'll not be able to tell whether the cuts are split or sawn!

Can you get clean cuts with a splitter ? If not will you be able to see them after ?

Just concious that I will have to hire a tool this weekend and want to get the right one.

I can, and, with a bit of practice, there's no reason why you shouldn't be able to. :)

What do other diy'ers feel? Are you happier with splitters or with cut-off saws?

I've ended up using angle grinder (which I already had) together with splitter. For my skill level, I found the problem was not "Do splitters give clean cuts?" (normally very), but more "Mmmm. Why did it choose to split there?". Occasional use of the angle grinder to skim a millimetre off reduced the amount of wastage (for me).

Another job where I found the nangle grinder/splitter combo worked well together was in cutting McCormack soldier corners, where one quarter of a block has to be removed with a 45 deg cut leaving a (relatively) delicate sticky-outy bit (technical term). Just marking out with a pencil or whatever and then submitting your block to the splitter produced extremely variable results (including beautifully aligned cuts but with the point missing, or beautiful point but the cut offset etc.). A careful score with the angle grinder (only a mm or so needed) to preload the stress into the top face of the block AND give you a determined guide for the splitter blade gave me results that I think would even get a grudging "Hmm. Alright" from himself.

Just my tuppence. It worked for me, but YMMV. A cut-off saw provides an alternative option I guess; as a 'when I can get a couple of hours' DIYer, I never felt the cost and inconvenience of hiring a c-o saw several times worthwhile. I did the arithmetic and bought myself a splitter - again, YMMV but for me that has paid for itself because my jobs have been very spread out (multiple hirings).

- Mike -

Finished at last, I would like to thank you for all your help and think the website is excellent for us DIY'ers.

One last question : I cracked a brick on the last pass of compacting and only saw this after I Keybonded. Whats the best way of dealing with it ?

P.S. I sent you some Pictures of the finished job

Abso-bloody-lutely superb! That is a cracking looking job, Ian. I like the interlocked diamonds, and the recess tray is spot on. Well done!



As for the one broken block, just flick it out with two trowels, as shown on the Repair page, and put in a new block. Sprinkle a handful of jointing sand around it, and leave it be. You'll need to top up the jointing sand for the whole drive in 6-8 weeks, so check it again then, and re-do the Keybond if you really think it's necessary.