Screed, is this a problem?

[hulkiebear]

Ok, so I started to build my oven today after a it of dry building of FB's before. I was sold what is a screed rather than a mortar, whilst I know it will go off fine and bond the bricks together, it does mean that I can not get it down into the fine point of the join of the cheese wedge(if you know what I mean). This means there will be a lots of very small cavity's within the wall.

Will this be a problem, I can't see why, but if anyone can answer before I continue, that would be great!

I have thought that I could grind down the screed in a morta and Pestal, so make it smoother, any thoughts?

Lee.

[dmun]

Re: Screed, is this a problem?

On this side of the pond, a screed is the board pulled over the top of a concrete form to level a slab. I've never heard the word used in conjunction with mortar, so i really don't know what you were sold. Is it a refractory product?

[hulkiebear]

Re: Screed, is this a problem?

In the UK, "screed" is what is known as a nearly dry concrete product, usually sharp sand(course building sand) and cement, it is used to make concrete floors, as you have a long time to level it.

It was suggested that I needed screed rather than a paste that starts to set on contact with air, because some of the gaps I would be filling would be fairly large(over 10mm) and the paste type product would not set properly!
Now I have a problem that I can't fill the very small end of the joint.

I'm happy that the "screed" product is suitable, it is a refractory product and in the shop I bought it(vitcas) there was a small cast oven, and the chap said, that is what the screed turns to. (not a small oven, but the material the precast shapes were made of)

So, do you think having small cavities in the oven wall will matter? they will not be air tight and above hearth level, so should not get anything in them.

[dmun]

Re: Screed, is this a problem?

Since you seem to be on uncharted ground, you should let us know what the product is you're using, and the results of using it, with photos if at all possible. We always like to know about new products and how they work.

[hulkiebear]

Re: Screed, is this a problem?

Will do, unfortunately, there is no label on the bag of the product, the guy in the warehouse at Vitcas, removed it when I ollected it, I assume to prevent people finding out their sources, I will take some photos and let you know. I am kinda comitted to the design and products I bought.

I have a plan, so, fingers crossed it works!

[hulkiebear]

Re: Screed, is this a problem?

I have gotten to use this screed(morter) to build the dome, well, I have started it, anyway.

the larger particules of the screed are a real pain, I can not get it right down to the tight corners, also, I can not use it as a even morter bed. I have tried to grind it with a pestle and morta, which works fairly well, but some parts in it, seem to be made of kryptonite, and will not! So, I have taken to sifting it, to make a smoother muck, then putting the larger bits in with more muck for the larger bits, that will easily take it. This process seems to work well.

I do find that the muck dry's out far to quick, I do soak the bricks, but it is not like laying normal bricks. Also, I find that the muck doesn't seem to bond to start with, but then, once it has gone off, forms a really strong bond! Infact, when I had built 3/4 of one of the archs, the next day it fell over to the side and did not break and seemed really tough!

It is not easy to work with, but the end product is just fine!

I added a photo of the sifted morter, large and small, I also found that it contained small fibres, like you get in toughened concrete to prevent cracking.