Roller screeds

[DaveGrohl]

What is the verdict on these for laying concrete? We've been using a vibrating beam screed for a lot of years for laying concrete with good results. Unfortunately the beam we have has got bent and either needs replacing or we go for a different system. The roller screed looks versatile in that you can have various lengths of aluminium tube lying around to suit the particular width of slab you need. Also I've seen that there is a DeWalt powered cordless version now which is intriguing me but I don't want buyer's regret if it's not up to the job, they're not cheap but look damn handy.

Keen for any advice from those in the know please.

 

[David.]

I have used both, and have gone back to a twin beam, actually made our own out of 6"x 3" aluminium channels.
That way we can gave access to a nice straight clean one every time, instead of putting up with the rubbish some hire firms send out and expect you to use.
Last time I used Bunyan roller was fairly disastrous, trying to lay a very sticky PAV mix for apron slab on a windy day.
Finish ended up like the top of a royal icing Christmas cake as the mix clung to the roller and flicked over and over, just couldn't get a finish that day. And the roller doesn't vibrate the slab enough either.

 

[upnortheast]

And the roller doesn't vibrate the slab enough either.

Watched one working one day & that was my thought.

 

[Lakesdigger]

There's no vibration on a roller screed they are purely for the surface finish if you're concrete suits obviously. If you want the finish of a roller screed you'd probably need a poker first. Imho beam screed far superior and will vibe conc.

 

[Sharpy]

If you are going to roller screed you MUST poker the concrete or vibrate in some way. The big advantage of a roller screed is the perfect finish and the fact that the aggregate tends to be aligned flat side up.
I have laid a lot of concrete with a magic screed, advantages include speed and no formwork required, especially handy against walls or doing the floors of a tank etc.

 

[pellow]

What will happen if the concrete is not vibrated when using a roller screed? We used one to build a silage pit nearly 20 years ago and I’m not sure there’s anything wrong with it

 

[Howard150]

If you are going to roller screed you MUST poker the concrete or vibrate in some way. The big advantage of a roller screed is the perfect finish and the fact that the aggregate tends to be aligned flat side up.
I have laid a lot of concrete with a magic screed, advantages include speed and no formwork required, especially handy against walls or doing the floors of a tank etc.

Magic screed every time. Only half the work and effort. Best used with a laser to check levels. Big Blue float after it.

 

[Sharpy]

What will happen if the concrete is not vibrated when using a roller screed? We used one to build a silage pit nearly 20 years ago and I’m not sure there’s anything wrong with it

If you have a good mix with a high design slump you will have few air pockets and hence a well settled slab. But you are supposed to use a medium slump with a roller screed.

 

[Sharpy]

Magic screed every time. Only half the work and effort. Best used with a laser to check levels. Big Blue float after it.

Yes, but some people don't like them. Ho hum.

 

[DaveGrohl]

Thanks for the replies. You've put me off so cheers. I can see the advantages of a magic screed in certain situations but it wouldn't be my preferred solution for general concreting.

Just out of interest, do people leave the concrete after the vibrating beam or go back and use a tamp bar for a tamped finish?

 

[upnortheast]

Generally finish with a light tamp. Usually cattle involved. Depends what you are doing

 

[DaveGrohl]

Generally finish with a light tamp. Usually cattle involved. Depends what you are doing

Yes I can see why it's necessary for grip for cattle but for say general yards?

 

[upnortheast]

General yard I would light tamp in the direction of the fall.
Brush finish is another option

 

[organicguy]

Thanks for the replies. You've put me off so cheers. I can see the advantages of a magic screed in certain situations but it wouldn't be my preferred solution for general concreting.

Just out of interest, do people leave the concrete after the vibrating beam or go back and use a tamp bar for a tamped finish?

Magic screed and rotating beam are not the same.
Used a magic screed once on a passage against walls and found it very difficult to get the falls I wanted but the concrete is still there so is probably good.
Get builder in now to lay concrete now. The big advantage of the rotating pipe is it does not move the concrete down the fall like a vibrating beam which means it can be laid wetter which means it is easier to lay. Is it as good, I don,t know?
We have some 5 years old, 150mm with steel, heavy use still intact, so initial impressions are it is ok.

 

[DaveGrohl]

Magic screed and rotating beam are not the same.
Used a magic screed once on a passage against walls and found it very difficult to get the falls I wanted but the concrete is still there so is probably good.
Get builder in now to lay concrete now. The big advantage of the rotating pipe is it does not move the concrete down the fall like a vibrating beam which means it can be laid wetter which means it is easier to lay. Is it as good, I don,t know?
We have some 5 years old, 150mm with steel, heavy use still intact, so initial impressions are it is ok.

Yes I understood that.

I think I've arrived at thinking areas of heavy traffic need vib screed but that we could use roller for certain jobs. Will I buy a rotating screed outfit? Nah, it was an either or purchase.