The Hole Truth

Had to rebuild a small part of a garden wall tother day, needed about 20 new bricks.

Found a pretty good colour match in Wickes, but instead of a frog the bricks had three 2" holes in them.

I can see a few benefits for Wickes - the brick must be cheaper to make (less clay) and you use more mortar.

I guess they would maybe make a stronger bond due to the mortar locking into the holes, but you can't allow an edge to show like normal bricks.

So why do they make them like that?

Reply to
The Medway Handyman
Loading thread data ...

Maybe they are extruded and have holes to make them lighter. I think the frog is in pressed bricks to make them lighter but it may reduce cracking during firing.

Reply to
dennis

I was told some years ago by a worker in our local brickworks that the frog was there to allow the heat during making to reach the centre of the brick. It had nothing to do with the bricks subsequent use. I was told the hole variety had holes for the same purpose. Does anybody know if this is true?

Reply to
.

I'm not an expert bricklayer - quite the reverse, but laying frogless bricks is far harder than ones with frogs as they tend to slip around more.

Reply to
Dave Plowman (News)

Insulation?

Reply to
Dave Plowman (News)

The only bricks I have come across with 3 holes in have been semi-engineering bricks - which are frost-resistant, and used below the DPC in houses, whereas bricks with frogs are usually either facing bricks or common bricks, and are used above the DPC.

(Semi-)Engineering bricks are fine (better than house bricks) for garden walls - as long as there's some sort of capping over the top - otherwise the holes will show!

Reply to
Roger Mills

You're supposed to lay them frog up!

Why on earth is it called a "frog" anyway?

T.

Reply to
tom.harrigan

The only bricks I have seen for years have the 3 holes. Everytime you see a pallet of bricks awaiting a brickie for a new extension etc, it is 3 holes. Also looking around builders yard, B&Q etc, 3 holes. Maybe it depends on the part of the country. Frogs use more mortar, and would be a pain using a bed template (like brickie tool etc). The video demo-ing this tool also has 3-hole bricks.

3-hole bricks will be wire-cut and a more consistent size, frogs will be made in the trad manner or repro. Simon.
Reply to
sm_jamieson

And the frog grips the mortar better so the brick can only slide on the mortar rather than the mortar sliding too.

Reply to
Dave Plowman (News)

I've also being told that laying brings with the frogs down (a common cheat on older building) saves 25% on mortar and reduce the strength by 50%.

Reply to
Ed Sirett

When I was shown how to lay bricks (in the early 1970's) all the brick-layers laid them frog down, perhaps things have changed since I was a yound lad...

I suspect that it's got something to do with the 'vee' shape, failing that, perhaps the origins of the depression is French!

Reply to
:Jerry:

Why should it reduce the bonding strength? Surely it's got more to do with the amount of mortar applied, although I can see that it's probably easier to skimp if you have a flat surface.

Reply to
:Jerry:

Probably more than 25% for deep frog bricks like LBC Flettons. As far as strength is concerned, this is very rarely a factor except under bearings and in narrow piers, and bricks should also be laid frog up below dpc level. In ordinary walls I wouldn't call it a cheat, just normal practice.

Reply to
Tony Bryer

Saves mortar: you don't HAVE to fill the frog with it..

The origin of *all* depression, is French.

>
Reply to
The Natural Philosopher

My father tought me that frog down was the southern way to lay bricks, to save on mortar. The proper way (as used in the north) is frog up, which is much stronger.

However, because of the voids, frog down is a better insulant.

Reply to
<me9

laid them frog down,

It uses less cement but you end up with an air space in each brick if the frog isn't filled (duh!).

I lived in a house once, and you could see the bricks change about 8' up. Below that the bricks were laid frog up as they are supposed to be (you can tell by the smiley face on hand-made bricks), then I presume the inspector came round and passed the building, and then all the bricks from there upwards were laid frog down so the bricks had the smile upside down. House is still standing - it was built in the late 70s - but I'm glad I don't live in it anymore

Reply to
Dave Gordon

The holes have multiple uses. They make the bricks lighter, and in some applications you can put rebar down them to reinforce the wall.. When the bricks are laid in one of the running bonds the holes roughly line up and you can put 6' rebar down the holes then cement it in.

Reply to
Dave Gordon

laid them frog down,

isn't filled (duh!).

Arguably better insulation.

Below that the bricks were

hand-made bricks), then I

bricks from there upwards

live in it anymore

IIRC you need to be careful with brickwork that is permananntly wet== below DPC. Above that it doesn't matter.

Lots of bricks have no frog anyway.

>
Reply to
The Natural Philosopher

There's no "supposed to" about it. They can be laid either way.

laid them frog down,

isn't filled (duh!).

The mortar saving from frog-down is about 10%. Some house builders require their brickies to lay frog down for this reason. For a novice brick layer, frog-up is easier.

Reply to
Andrew Gabriel

In article , Andrew Gabriel scribeth thus

What.. is the purpose of the "frog" anyway?......

Reply to
tony sayer

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.