Bricks. Which side up?

[michael]

I was advised by a builder today that when he lays his bricks and lime mortar he always lays the bricks with the ‘frog’ (recessed side) facing down.
His theory is that if the brick is laid with the frog side up and if the frog is not completely filled with mortar then it creates a cavity which could potentially collect water and therefore be prone to frost damage. He assured me that his down turned frog’s attained sufficient mortar within them when they were tapped down into place in the lime mortar bed.
I always assumed that bricks were laid frog side up. Has anybody else heard of this practice?

 

[Penners]

No, I haven't heard of it before. But it seems to me that that there is a counter-argument to your builder's theory.

If you have the frog at the top, then it's easy to fill it with mortar as you "butter" the course. If it's on the bottom, you have to try and bulk up the mortar that you've buttered on to the course below, in order to ensure that some of it rises into the frog. Gravity is working against you. I could also envisage that an airlock could prevent the mortar from rising fully into the frog.

Surely the answer is careful mortaring on to an upward-facing frog!

 

[CatherineB]

I've been desperately trying to find a picture of an upside down kermit, but bing and google failed me

Clearly frogs are meant to be the right side up

 

[MdB]

 

[essexbearhunter]

Whilst everyone seems to have their opinions - including a gentlemen who opted for Frog-down because it helped stop the brick from "drifting out of position" before the mortar had set off - the official line is:

If the bricks are laid according to British standards, the frog should be laid upward and filled with mortar.

British Standard Code of Practice BS 5628-3 states. “Unless otherwise advised, lay single frog bricks with frog uppermost and double frogged with deeper frog uppermost. Fill all frogs with mortar…” This maximizes strength, stability and general performance of the brickwork.
Why frog should be laid upwards:

When the frog is laid upwards, the load is evenly spread throughout the width of the brick all the way down to the foundations. If the frog is laid down, the load is forced to the outsides of the brick.

The figure shown below can tell how the load is evenly spread and how it is forced to the outsides of brick.

(see URL for picture)

http://www.civilengineeringterms.co...-should-be-laid-upwards-course-mortar-joints/

 

[MdB]

Might as well have the pic here:

 

[Lime]

Going back in time to the tv programme Crossroads, didn't the wall that collapsed on Sandy have it's frogs laid down?

 

[LadyArowana]

Perhaps you should do away with the bricks completely and just build something imaginative out of the frogs?

 

[AMc]

I've never heard of this but then the "traditional" bricks used in my house with lime mortar don't have frogs!
IMHO I'm not convinced there is any benefit to this as I can't see frost getting to the centre of the brick in the first place but I can't see it being terribly detrimental either.
If he's working for you then I suggest you ask him to do what you are most comfortable with.
If you want a second opinion then I found Mike Wye to be very helpful with lime mortar advice before I ordered from them - it might be worth contacting a lime supplier or two if you're concerned.

 

[middi]

The reason why lazy" brikies" lay bricks frog face down is because the use less mortar and, most importatnt, if they are working with soft and highly absobent bricks it is much easier to " settle" the brick when only the thin edge of the brick is in contact with the faster drying mortar, ie- working faster.

Middi

 

[stuart45]

I would say that the majority of bricklayers in the past on price work laid them frog down. Back in the 70's the London Brick Company did some tests and said that on buildings up to 2 storey their bricks could be laid frog down witha 30% reduction in mortar. There used to be some really heated arguments on site between subbies and the CoW's.

 

[biffvernon]

Some of us would never use a brick with a frog. Nasty modern machine made things.

(Re the OP, there's no way that an upward frog could contain a puddle of water - try it and see how quickly the water leaks out.)

 

[Penners]

So, Michael - just tell your builder that you're on to his game!