Concrete blockwork using polyurethane glue for shed?

[Henrik]

So if I understand correctly, it is nowadays possible to find polyurethane glues that will glue blockwork together. Certainly youtube has videos on Americans and Europeans using gun-grade PU to fix blocks together.

Is that something that is available or used in the UK?

I'm trying to decide between a blockwork or wooden shed, and I'd quite like the blockwork due to fire resistance, however I also do not want to spend months and months laying blocks. The glue route would appear to be the easiest way for a dilettante such as myself.

With PU holding both in compression and tension, would the wall using block+PU perhaps even be stronger than block+mortar?


The shed size would be somewhere in the region of 4.5-5m wide, and about 2.5-3m deep.

 

[EM1L4]

Just found this, https://www.thomasarmstrongconcreteblocks.co.uk/thin-joint-construction.html

sounds interesting, i wonder if its more expensive?

 

[gaz1]

basically this size shed done in a few days cement method and no we are not brickys

but we do other jobs as well as joinery

 

[bigegg]

I've glued paving slabs to the top of a low wall to make a seating area using PU "construction adhesive". Seems to be solid (two years later).
Aternatibely, Sikaflex will hold anything together, in my experience.

But: as @gaz1 intimates, building walls out of blocks is a doddle.
4:1 sand:cement in a wheelbarrow, mixed with an English hoe, and you'll be surprised at how fast it'll go up.

 

[gaz1]

building your corners first is the most important thing
the rest inbetween dosnt matter its just a string line inbetween them

make your mix wet enough and its place blocks and gently wiggle them into place if you have to hit the block hard then the mix is too dry should be able to just tap it with a trowel to level it

build it half way first day then the second full height the next day

 

[CompoSimmonite]

I found a company making large versions of the tiling spacers who sent me a selection of the types available. I reckoned that I could dry lay hollow concrete blocks using such spacers, use a pointing gun to fill the gaps and then fill the space between the hollow blocks with a wet, fine, concrete mix

 

[gaz1]

 

[Henrik]

hmm, yes, maybe i should just lay blocks like normal... it can't be all that difficult, right?

The only thing that worries me about block walls is really the time it will take me... I only get the odd couple of hours here and there, so anything that is, say, 50% slower, will mean probably weeks/months of extra build time before finished.

Having said that, maybe I should just book some holiday and do it...

 

[gaz1]

no offense here even with a few hours once those corners are built you can lay a coarse or 2 really easily and quickly

its getting those corners straight and level in the first place that you spend the most time doing dont be finiky either

bricks and blocks are not truly level or flat so the method is follow line or level guides

 

[bigegg]

no offense here even with a few hours once those corners are built you can lay a coarse or 2 really easily and quickly

its getting those corners straight and level in the first place that you spend the most time doing dont be finiky either

bricks and blocks are not truly level or flat so the method is follow line or level guides

Pile em up, something like, then render it.
That way, you can claim all the non flat/level blocks are to provide a key for the render.

 

[EM1L4]

A wise person once told me how long would it take a professional? What’s your time worth vs paying someone to do parts of the work? I should say that was after they spent weeks doing their own block work and realising a professional would have had it done for a few days pay instead of weeks of them doing it in their valuable spare time

 

[DanZac]

I'd have though the cost of the glue would cover paying someone to build it for you properly.
How many blocks are you going to be able to stick down per tube of PU?

 

[My Old Landy]

I can't help with the original question but I got a brickie to lay the bricks on my workshop for a fixed fee. I did the labouring (I was fit back in 2004!) and he built it in 10 days. I mulled over doing it myself as I had laid the foundation pad. I also made all the doors and windows and put the roof on. I knew I would take too long so I paid for the tricky bit!! Hope all goes well with your build no matter what you chose to do

 

[cheb]

One advantage of the PU, assuming it doesn't go off in the tube once opened, is that you could lay one block and walk away if need be and not waste a mixer load of mortar.

 

[grim_d]

no offense here even with a few hours once those corners are built you can lay a coarse or 2 really easily and quickly

its getting those corners straight and level in the first place that you spend the most time doing dont be finiky either

bricks and blocks are not truly level or flat so the method is follow line or level guides

It's the prep and cleanup that probably hinders it though, get all the guff out, mix a bit up, clean all your guff down, gets old real fast if just laying a few blocks

 

[frank horton]

don't thei also use a cement slurry.......?
personally I make a frame of 150x50x3mm box and then bolt insulated panels to it.....
real quick, no hastle...do it once an finish....
hardest part is painting the welded frame....hahaha....
if there's two of u, once the frame is up ALL the panels would be on in a day....

 

[Rudi McAnichal]

Pile em up, something like, then render it.

Saw this demonstrated in the late 1970s by the Cement & Concrete Association (now called BCA). They laid blocks dry and rendered the wall on both sides using reinforced plaster containing (I think) glass fibres. Very quick to build, hardly any training required for the person stacking the blocks, and the finished wall was said to be stronger than blocks and mortar.

Main problem for me -- I’ll tackle most DIY building jobs, but am totally useless at plastering. The professional flicks a trowel full of plaster at a wall, and it sticks. When I try, most of it falls on the floor.

https://www.sakrete.com/blog/from-the-ground-up-how-to-build-a-drystack-wall

 

[pedrobedro]

hmm, yes, maybe i should just lay blocks like normal... it can't be all that difficult, right?

The only thing that worries me about block walls is really the time it will take me... I only get the odd couple of hours here and there, so anything that is, say, 50% slower, will mean probably weeks/months of extra build time before finished.

Having said that, maybe I should just book some holiday and do it...

When I did mine I did a mix and found it would lay 9 blocks so I did one in the morning and one in the afternoon most days and I finished my blockwork in about 3 weeks. Hollow blocks you can stack then knock rebar down the cavities and fill with cement slurry, method used for retaining walls

 

[gaz1]

It's the prep and cleanup that probably hinders it though, get all the guff out, mix a bit up, clean all your guff down, gets old real fast if just laying a few blocks

theres nothing in the prep or clean up its get your gear ready the night before like any other job in the building trade

get home grab the gear get a mix ready and get cracking for wash off thats easy dip trowel in bin water and wash it off that way ligger board ( cement wod board ) scrape off the next day

barrow and shovel weel pour water into wheel barrow wash shovel and trowel in there brush it off tip it out not much really to do

 

[Pete.]

I can't see how laying blocks with PU can be any easier than using mortar. Certainly the mortan is fully compatible with the block material and won't suffer from UV degradation.