Blockwork half course & '100mm' blocks

[i_am_fubar]

I am building my workshop out of 215mm x 100mm blocks.

I want to maximise my permitted development height allowance by adding 100-150mm extra wall height

100mm Concrete blocks are the usual 95mm wide.

100mm bricks are 103mm wide.

I don't want to cut all my blocks length wise.

I can't seem to source dolly blocks in Hampshire UK.

What options do I have for finding 100mm wide (but actually 95mm) blocks/bricks?

Ta

 

[robinbanks]

You're dithering over 8mm, which will be 4mm by the time you've finished splitting it between front and back. There will be parts of the wall more than 4mm out of plumb, that will disappear into the rendering/wall covering

If you're leaving it bare, and a 4mm variation will genuinely annoy you forever more, put your rows of concrete commons at the bottom of the wall, or take less than an hour out of your life to stihl saw a load of blocks in half. It's real quick if you lay them out in a line and just cut them in a one-er

If you haven't poured the founds yet you can do it there too, or you can fit a thicker wall plate and nail a bigger decorative topping over it etc

 

[noseall]

What options do I have for finding 100mm wide (but actually 95mm) blocks/bricks?

Have you looked at concrete commons or lightweight coursing bricks?

 

[^woody^]

Bed up, like this one I did last week

 

[Ivor Windybottom]

The concrete bricks I have are supposedly 103mm nominal width. In reality they're exactly 100mm.

Even if they're 103mm then that makes precisely bugger all difference.

 

[i_am_fubar]

I love how peeps are saying 8mm makes bugger all difference. A wall deviation of 8mm makes fitting shelves and brackets an absolute bastard and looks like a dog if there's any hint of low angle light on it.

If I was putting thick render or dot and dab on, I'd be inclined to agree, but for the most part my walls are plumb and flat to a couple of mm and I would prefer to not have such a step, especially as the '100mm' timber for the wall plate is only going to be 95 again. (Call me anal for aiming for perfection if you must )

I'll grab a few concrete common bricks (not lightweight, all blocks are dense concrete) and see how they look.

Dolly blocks look perfect, but seemingly unavailable in the south of England.

 

[Ivor Windybottom]

You could have cut all your blocks to whatever height you needed by now. Exactly the right width, perfect height, matching colour.

Obviously cut the underside and wash them with the hosepipe before use.

 

[noseall]

You could have cut all your blocks to whatever height you needed by now. Exactly the right width, perfect height, matching colour.

Obviously cut the underside and wash them with the hosepipe before use.

It's the width of the masonry at issue here I.e.103mm v's 95mm.

 

[noseall]

I'll grab a few concrete common bricks (not lightweight, all blocks are dense concrete) and see how they look

You're welcome.

 

[cdbe]

It's 2.5m above the highest adjacent natural ground, which looks like the bit at the back - so depending how high you are now and your roof, you could probably add two more courses if full blocks without issue.

 

[Ivor Windybottom]

It's the width of the masonry at issue here I.e.103mm v's 95mm.

He's got 95mm width blocks that are 215mm tall. Chalk or wax crayon, disc cutter or angle grinder with a diamond disc, job done.

In fact an accurate half-way would be about 105mm high after losing the blade width, may be perfect so you get two blocks from each cut.

Half-hour of a job. Worth making a wooden chopping block with a nailed on batten to hold them against. Fit an end stop and cut a guide groove, then you don't even need to mark them up.

 

[Ivor Windybottom]

The ground level thing is ambiguous. I don't think it's actually stated as original or natural ground level, which is a gaping loophole.

Build something sensible, chances are absolutely nobody will care if it's a smidge over. If anyone does complain then put some more soil or paving slabs next to it.

 

[noseall]

He's got 95mm width blocks that are 215mm tall. Chalk or wax crayon, disc cutter or angle grinder with a diamond disc, job done.

Perhaps you never got the memo...

I don't want to cut all my blocks length wise.

hence....

Have you looked at concrete commons or lightweight coursing bricks?

 

[robinbanks]

Who was the first person to mention concrete commons?

Call me anal for aiming for perfection if you must )

OK

Your sub base looks about 3mm low in the back corner there. Keep that lack of precision up and you'll have the leaning tower of pisa on your lap by the time you're 4 courses up!

Worth making a wooden chopping block with a nailed on batten to hold them against.

I probably wouldn't go to that level of precision, just run the cut using a scratched guide and put the cut face bed side down at the bottom of the wall so any millimetre deviations disappear before they have a chance to upset anyone!

 

[i_am_fubar]

I'm measuring my final height from the pavement on the other side of the fence. 2.5m up. This gives me 100mm insulation on flat roof, and a ~2.5m ceiling height when I account for the joists.

Well, if I use full blocks it's 2.6m roof hight. If I loose a row it's 2.37m and my internal 2.5m ceiling drops under 2.4m

I don't want less than 2.4m because.... Principle

Will get the 10th course in and assess from there based on your replies. Cheers all!

Also, apparently dolly blocks are also called soap bar blocks, so can search for them too.

With respect to cutting them... So much dust, so much noise :/