What to use instead of snap ties

[sirocosm]

New to the UK, and I am pouring a grade beam for a workshop that I am building. In Canada (the land of basements), concrete forms are made of 3/4 plywood held together with snap ties, that have slots in them that you slide flat metal bars (waler bars) that hold the forms at a fixed distance. After the concrete sets, you slide the bars out and snap off the ends of the ties.

What do they use in the UK for this purpose?

 

[^woody^]

What's a grade beam?

What's the purpose of those bars in relation to that grade beam?

 

[sirocosm]

A grade beam is a small concrete wall. In my case it will be 60cm high 25cm thick, with about half under ground (grade), sitting on a footing. Not sure what they are called here.

Here is a pic of how the snap ties are placed.

 

[^woody^]

A retaining wall then? Or just a concrete wall.

I've never come across those ties. We tend to just shutter concrete with bracing externally and not through the wall.

Won't those ties end up rusting due to the exposed ends?

 

[sirocosm]

It is for a short concrete wall that will be the foundation for the workshop.

The snap ties break off just below the surface, and the holes are normally just filled, but you can also get stainless ones.

 

[JohnD]

there is a method of using threaded studding, with screw-on plates that clamp against the shuttering on both sides, and sometimes people use wire.

 

[Scarlet Pimpernel]

Will wall ties work?

https://www.screwfix.com/p/sabrefix-wall-ties-200mm-for-50-75mm-cavity-50-pack/62409

or hire the proper thing.
http://www.aluminumconcreteforms.com/

 

[^woody^]

It just seems like a waste of time. I can't see any advantage in it at all.

 

[sirocosm]

Will wall ties work?

https://www.screwfix.com/p/sabrefix-wall-ties-200mm-for-50-75mm-cavity-50-pack/62409

or hire the proper thing.
http://www.aluminumconcreteforms.com/

Those ties are an idea, cheap and won't rust. Probably strong enough if you use enough of them.

 

[sirocosm]

It just seems like a waste of time. I can't see any advantage in it at all.

If you have ever seen forms put up with snap ties and whaler bar, it is hard to imagine a quicker way to do it. Plus it is mostly just plywood, and you do not need so much additional bracing, just enough to keep the forms in place.

Without any anchors through the wall, there is a lot of outward pressure on the forms, especially at the bottom. Adding all that bracing externally seems like it would take a lot of time, and material.

 

[^woody^]

If you have ever seen forms put up with snap ties and whaler bar, it is hard to imagine a quicker way to do it. Plus it is mostly just plywood, and you do not need so much additional bracing, just enough to keep the forms in place.

Without any anchors through the wall, there is a lot of outward pressure on the forms, especially at the bottom. Adding all that bracing externally seems like it would take a lot of time, and material.

I've seem shuttering go up quick and and for large and small panels and beams alike, without his method.

But what I meant was it seems a lot of work and a waste of time to do all this as some sort of base for a workshop, when a simple trench, poured concrete and then a bit of masonry would be much simpler. What is the advantage of this grade beam for a simple outbuilding?

 

[sirocosm]

Sorry, I thought you meant the forms.

The workshop will be of wood construction, rendered with a clay tile roof to match the house. The idea is to get it 30cm or so off the ground so that it doesn't rot.

You are right, it is probably overkill, but I have no experience with block, and concrete is around the same price if you can re-use most the wood from the forms.

 

[^woody^]

Consider it a chance to learn something new! And better

I've just had a look at a "grade beam" and it seems to be some sort of foundation built on top of, or just a small part below the ground surface. Pictures show it reinforced too.

I think the equivalent for us would be "ring beam" concept but used in a slightly different way.

Anyway, you would need to be sure that UK ground is suitable for this grade beam concept as it looks very shallow, so I wonder if its only suitable for certain [harder more stable] ground. But It looks like you can do this without the ties and just stake the shutter and brace the sides over the top.

 

[sirocosm]

Although in Canada people tend to call any concrete wall buried half in the ground a grade beam, technically the name really applies to a steel reinforced structural beam that can span the distance between piers or something like that.

In my case it will be supported by a footing all along, but I will still put some steel in it anyway. The footing is 30cm thick and 60cm wide, so the bottom will be about 60cm below grade.

 

[Bluepeppo]

Dywidag shuttering