Re: poroton
[SUEELLEN, HOW ABOUT RENAMING THIS THREAD "POROTON BLOCKS", MIGHT BE A BETTER GUIDE TO OTHER USERS]
Hi heinbloed,
I have not been posting much lately due to blocklaying duties!
Using SX12 block, external only, 365x250x250mm.
Yes, can use chipped blocks, repairing with the LM21, but would not chance ones that have lost more than a bit of the outer edge.
At this point have installed the ring beam on the second storey and am now in the welcome position of actually waiting for someone else to do work before I can finish the job (need the roofer to set the guide rafters so we can do the gables).
All told, the project is going well. I built the two 2-storey extensions to ring beam in about 18 working days (with help, you need someone to get the blocks up to you, to mix the glue, and to generally keep you sane when thing go awry). There were some problems along the way, which slowed things down: we went off level, meaning much shimming up of blocks in certain parts of the wall. Don't know how this happened but it did... Certainly very hard to stay level once you cut a block vertically (as you may have to do over lintels) or once you move off the thin-joint mortar to the LM21 in a single course (again over lintels, for example). But the trick is, don't panic, remind the blocks that YOU are in charge (hey, you do a lot of talking to yourself when you're self building, and I mean literally self building!).
There is a huge amount of satisfaction attached to doing it yourself. This can be tempered by the sceptical comments of other subcontractors as they arrive on site and inspect your work. Nobody, apparently, has "ever seen the likes of them blocks before." Happily, the sceptics are starting to admire the blocks now, having seen the method. And if you are building in a part of the country where it's difficult to find subbies and labourers (despite so-called local economic hardship), you get a bit of kudos from disbelieving building pros for doing it yourself and moving the overall project along.
But we're not out of the woods yet. Still got to do those gables. Glad you had blocks left over heinbloed - me, I'm about 150 blocks short right now, due perhaps to the large number of broken blocks in my original deliveries. (150 blocks is a lot, nearly 10 sq metres worth). Luckily another local FBT client has about 150 blocks left over, so I'll be able to do a deal with him. Coincidence?
Generally, FBT have been fantastic people to deal with with regards to taking time to answer my sometimes very naive questions. However this is to be expected as they actively encourage people to do it themselves. Wolfgang (the German with the Wexford accent) is always available to help with queries.
My considered opinion? Doing your own blocklaying is not for the faint-hearted. Very hard and heavy work. You need a helper. If you have to pay the helper the cost savings are obviously reduced, especially if things go slowly. Then again, try getting a blocklayer to quote you on poroton blocks! Not easy. Would I do it again? I doubt it.
heinbloed, did you buy the external waterproof render from FBT or from elsewhere? Obviously the render is critical for a single leaf construction method to work, so I'd like to know your experiences both with your plasterer and aslo with living in the building afterwards. The blocks are very porous and seem to suck in water so the external plaster is vitally important. How'd it go for you?
And what about such mundane things as putting in vents and making outlets for waste pipes etc. How did you achieve same?
Interested to know.