Bricking being a rare occurrence in my DIY repertoire, I am curious about
the various designs of the bricks. Why do some have holes going right
through, and others just hollow 'frogs' on one side.

My builder bro in law tells me the frogs are supposed to face upwards, but
could not give me the reason why. My 'common sense' view would have been
that, were there to be any missed bits in the mortaring, or should cracks
develop, frogs facing upwards would tend to collect water that might break
up the wall if frozen while still wet. Also, laying 'frogs down' gives me a
flat top to any little bits of bricking I do around the garden - though
'frogs up' would give a better key to any final layer of coping stones, so
that might be the reason I suppose.

What is the reasoning behind frogs, their design and positioning while
laying?

Cheers,

S

Spamlet wrote:
Bricking being a rare occurrence in my DIY repertoire, I am curious
about the various designs of the bricks. Why do some have holes
going right through, and others just hollow 'frogs' on one side.

My builder bro in law tells me the frogs are supposed to face
upwards, but could not give me the reason why. My 'common sense'
view would have been that, were there to be any missed bits in the
mortaring, or should cracks develop, frogs facing upwards would tend
to collect water that might break up the wall if frozen while still
wet. Also, laying 'frogs down' gives me a flat top to any little
bits of bricking I do around the garden - though 'frogs up' would
give a better key to any final layer of coping stones, so that might
be the reason I suppose.
What is the reasoning behind frogs, their design and positioning while
laying?

Cheers,

S

All frogs and holes are there for two reasons, firstly to create a bond,
rather than just a flat surface, and secondly, to save clay during
manufacture.

London bricks have one flat side and a hollow side, IME, the frog should
face downwards, to save on mortar and to create a better bond, but that
said, London bricks shouldn't be used for garden walls - they are too soft
and will blow apart within a year or two due to frost / defrost cycles

On 29 Aug, 15:15, "Phil L" wrote:
Spamlet wrote:
Bricking being a rare occurrence in my DIY repertoire, I am curious
about the various designs of the bricks. Why do some have holes
going right through, and others just hollow 'frogs' on one side.

My builder bro in law tells me the frogs are supposed to face
upwards, but could not give me the reason why. My 'common sense'
view would have been that, were there to be any missed bits in the
mortaring, or should cracks develop, frogs facing upwards would tend
to collect water that might break up the wall if frozen while still
wet. Also, laying 'frogs down' gives me a flat top to any little
bits of bricking I do around the garden - though 'frogs up' would
give a better key to any final layer of coping stones, so that might
be the reason I suppose.
What is the reasoning behind frogs, their design and positioning while
laying?

Cheers,

S

All frogs and holes are there for two reasons, firstly to create a bond,
rather than just a flat surface, and secondly, to save clay during
manufacture.

London bricks have one flat side and a hollow side, IME, the frog should
face downwards, to save on mortar and to create a better bond, but that
said, London bricks shouldn't be used for garden walls - they are too soft
and will blow apart within a year or two due to frost / defrost cycles

I was told that frogs should not be used downwards, since all the
force is carried by the edges, unless the frog is totally filled,
which is very unlikely, especially if your aim is to save mortar.
Also, if the edges spall badly for any reason, you can lose a lot of
your load-bearing face. So frogs should be used upwards and completely
filled.
Fine to use frogs down for a top row where the upper face will be
seen .
My house is built entirely with bricks with no frogs or holes (from
the now-defunct Leamington Brick Co. (stamped on them !)

For the bricks with holes, I have noticed the holes seem to be getting
bigger. I think they are now made with the maximum allowable voids,
which is specified in some BS or other.

Simon.

In article ,
Phil L wrote:
London bricks have one flat side and a hollow side, IME, the frog should
face downwards, to save on mortar and to create a better bond, but that
said, London bricks shouldn't be used for garden walls - they are too
soft and will blow apart within a year or two due to frost / defrost
cycles

I've got lots of ornamental garden brickwork all made out of secondhand
stocks. No problems whatsoever. In over 20 years. And many much older than
that garden walls round here - in varying states of repair, that's true -
but then that applies to ones made of other bricks too.

--
*A day without sunshine is like... night.*

Dave Plowman London SW
To e-mail, change noise into sound.

Spamlet wrote:
Bricking being a rare occurrence in my DIY repertoire, I am curious about
the various designs of the bricks. Why do some have holes going right
through, and others just hollow 'frogs' on one side.

My builder bro in law tells me the frogs are supposed to face upwards, but
could not give me the reason why. My 'common sense' view would have been
that, were there to be any missed bits in the mortaring, or should cracks
develop, frogs facing upwards would tend to collect water that might break
up the wall if frozen while still wet. Also, laying 'frogs down' gives me a
flat top to any little bits of bricking I do around the garden - though
'frogs up' would give a better key to any final layer of coping stones, so
that might be the reason I suppose.

What is the reasoning behind frogs, their design and positioning while
laying?

Cheers,

S


I did post a few weeks (maybe months now!) ago - a detailed document
form one of the brick making companies. In summary:

Absolutely always frog up - but if some nifty corner or something meeds
to go the other way, fill the frog completely and carefully slide the
brick off the trowel.

Many bricks 'grin' such that if they are laid not frog up, the face of
the brick looks wrong.

Therefore, no saving in mortar.

AIUI, the frog was more to ensure that the brick fired more easily -
i.e. the middle of the clay got hot enough. That to some extent explains
why holes can have the same effect. Frogs might have saved clay and
transport costs as well - but to the end user the increase in mortar
usage probably offset that to a considerable extent.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

"Dave Plowman (News)" wrote:

In article ,
Phil L wrote:
London bricks have one flat side and a hollow side, IME, the frog should
face downwards, to save on mortar and to create a better bond, but that
said, London bricks shouldn't be used for garden walls - they are too
soft and will blow apart within a year or two due to frost / defrost
cycles

I've got lots of ornamental garden brickwork all made out of secondhand
stocks. No problems whatsoever. In over 20 years. And many much older than
that garden walls round here - in varying states of repair, that's true -
but then that applies to ones made of other bricks too.


I can see why London bricks should not be used for retaining walls,
but for a free standing wall on a well drained base, there should not
be any problem.

They built millions of houses with them, plus public buildings of all
kinds, so I really don't think their durability is in doubt to the
extent that was alleged.

wrote:
On 29 Aug,
Rod wrote:

AIUI, the frog was more to ensure that the brick fired more easily -
i.e. the middle of the clay got hot enough. That to some extent explains
why holes can have the same effect. Frogs might have saved clay and
transport costs as well - but to the end user the increase in mortar
usage probably offset that to a considerable extent.

My father always said frog up -- the other way up was for southern penny
pinchers.

Recent information indicates that for energy saving reasons (and a slightly
lower strength wall) that the frog should be down (thus creating insulating
voids). For maximum strength when needed frog up.


I have not checked out thermal insulation qualites, but the info. I
posted is clear on acoustic insulation - frog up. In fact, the document
is crystal clear that only frog up is acceptable in almost all
circumstances for a variety of reasons.

I replicate my post from 2 July this year:

Funny that - probably why Ibstock bother to produce Technical
Information Sheet 25 - text below, with pictures if you go to the PDF
itself. I have no idea whether three hole bricks are becoming more
common but they certainly have not entirely replaced frogged bricks.

Laying €˜frogged bricks

British Standard Codes of Practice BS 5628-3 The Use of Masonry and BS
8000-3 Workmanship on Building Sites state that "Unless otherwise
advised, lay single frog bricks with frog uppermost and double frogged
with deeper frog uppermost. Fill all frogs with mortar....."

Bricks walls built with frogs down and unfilled are weaker and less
resistant to sound transmission.

Advice should be sought as to whether bricks laid frog down are acceptable€�.

Many bricklayers prefer to lay bricks frog down as they believe it to be
a faster method and it uses less mortar. However the performance of the
brickwork can be affected by insufficiently filled frogs.

Strength and stability

Compressive strength tests on frogged bricks have traditionally required
them to be fully filled with mortar beforehand. The resulting figures
are used by engineers in calculating the loads brickwork can support.
Brickwork with unfilled frogs will fail at lower loads.

Sound Insulation

Changes to the Building Regulations for England and Wales in 2003
require dwellings to be constructed to new Standards so as to reduce the
levels of transmission of sound between and within dwellings.

For solid masonry walls the resistance to airborne sound depends mainly
on the mass per unit area of the wall (density).

To maximise this:-

o fill and seal all masonry joints with mortar.
o use bricks that extend to the full thickness of the wall.
o lay brick frog up to achieve required mass per unit area and avoid
air paths.

Fixings to Brick Walls

Fixings to walls must be used with care so as not to disrupt the brickwork.
The whole structure is less fragile when the voids are fully filled with
mortar and there is maximum bonding of all surfaces.

Aesthetics

When laid correctly, the creases on the face of handmade or simulated
handmade bricks form a €˜smile. Aesthetically it will look better if all
the bricks are uniformly laid but will also help to shed water.

Exceptional circumstances

In very exceptional circumstances It is possible to lay bricks
with the frog down and fully filled but it can be time consuming and
suitable for particular details only i.e. if €˜handed bricks are not
available for either side of an opening it may be possible to invert
some on one side.

This may not be acceptable for some textured products.

To lay bricks with frogs down and filled, the trowel must be loaded with
sufficient mortar and brick and trowel lowered into position.

For further help and advice contact the Technical Services Helpline on
0844 800 4577.

Issue 2 Sept 2007

http://www.ibstock.com/pdfs/technical-support/TIS-25-Laying-frogged-bricks.pdf


--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Dave Plowman (News) wrote:
In article ,
Phil L wrote:
London bricks have one flat side and a hollow side, IME, the frog
should face downwards, to save on mortar and to create a better
bond, but that said, London bricks shouldn't be used for garden
walls - they are too soft and will blow apart within a year or two
due to frost / defrost cycles

I've got lots of ornamental garden brickwork all made out of
secondhand stocks. No problems whatsoever. In over 20 years. And many
much older than that garden walls round here - in varying states of
repair, that's true - but then that applies to ones made of other
bricks too.

LBC won't guarantee bricks used for garden walls, and most brickyards will
tell you this if you ring and enquire....stock brick aren't made by LBC,
even though they do have a slight frog, sometimes on both sides.

Lots of bricks are suitable for garden walls, almost all of them are not
very porous, LBC bricks are like digestive biscuits

Bruce wrote:
"Dave Plowman (News)" wrote:

In article ,
Phil L wrote:
London bricks have one flat side and a hollow side, IME, the frog
should face downwards, to save on mortar and to create a better
bond, but that said, London bricks shouldn't be used for garden
walls - they are too soft and will blow apart within a year or two
due to frost / defrost cycles

I've got lots of ornamental garden brickwork all made out of
secondhand stocks. No problems whatsoever. In over 20 years. And
many much older than that garden walls round here - in varying
states of repair, that's true - but then that applies to ones made
of other bricks too.


I can see why London bricks should not be used for retaining walls,
but for a free standing wall on a well drained base, there should not
be any problem.

They built millions of houses with them, plus public buildings of all
kinds, so I really don't think their durability is in doubt to the
extent that was alleged.

Have a look at houses built with them 20 - 30 years ago, almost all of them
have had bricks replaced over the years due to blowing....the ones below DPC
are usually mangled

Phil L coughed up some electrons that declared:

Bruce wrote:
"Dave Plowman (News)" wrote:

In article ,
Phil L wrote:
London bricks have one flat side and a hollow side, IME, the frog
should face downwards, to save on mortar and to create a better
bond, but that said, London bricks shouldn't be used for garden
walls - they are too soft and will blow apart within a year or two
due to frost / defrost cycles

I've got lots of ornamental garden brickwork all made out of
secondhand stocks. No problems whatsoever. In over 20 years. And
many much older than that garden walls round here - in varying
states of repair, that's true - but then that applies to ones made
of other bricks too.


I can see why London bricks should not be used for retaining walls,
but for a free standing wall on a well drained base, there should not
be any problem.

They built millions of houses with them, plus public buildings of all
kinds, so I really don't think their durability is in doubt to the
extent that was alleged.

Have a look at houses built with them 20 - 30 years ago, almost all of
them have had bricks replaced over the years due to blowing....the ones
below DPC are usually mangled

Mine are fine, from 1950, all LBC "rustics".

Now, the pointing - that's another storey.

Cheers

Tim

On Fri, 29 Aug 2008 17:54:41 +0100 Bruce wrote :
I can see why London bricks should not be used for retaining walls,
but for a free standing wall on a well drained base, there should not
be any problem.

They built millions of houses with them, plus public buildings of all
kinds, so I really don't think their durability is in doubt to the
extent that was alleged.

LBC Flettons are fine if they're not saturated, i.e. in a house wall where
the roof overhangs protect the brickwork, but if you use them in a coping
or build a wall with an unprotected top they will disintegrate over time.
They are cheap because the clay contains a certain amount of carbon which
reduces the firing needed (as does the deep frog) but as this burns away
during the firing it leaves a relatively porous core to the brick.

London stocks are a completely different sort of brick and generally much
more durable.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

"Phil L" wrote:

Bruce wrote:
"Dave Plowman (News)" wrote:

In article ,
Phil L wrote:
London bricks have one flat side and a hollow side, IME, the frog
should face downwards, to save on mortar and to create a better
bond, but that said, London bricks shouldn't be used for garden
walls - they are too soft and will blow apart within a year or two
due to frost / defrost cycles

I've got lots of ornamental garden brickwork all made out of
secondhand stocks. No problems whatsoever. In over 20 years. And
many much older than that garden walls round here - in varying
states of repair, that's true - but then that applies to ones made
of other bricks too.


I can see why London bricks should not be used for retaining walls,
but for a free standing wall on a well drained base, there should not
be any problem.

They built millions of houses with them, plus public buildings of all
kinds, so I really don't think their durability is in doubt to the
extent that was alleged.

Have a look at houses built with them 20 - 30 years ago, almost all of them
have had bricks replaced over the years due to blowing....the ones below DPC
are usually mangled


Below DPC, I can understand. But elsewhere, as long as they are not
in, or supporting damp ground, I don't think they are really any worse
than most other facing bricks. Are they?

In article ,
Bruce writes:

I can see why London bricks should not be used for retaining walls,
but for a free standing wall on a well drained base, there should not
be any problem.

Garden walls have more stringent requirements for bricks,
or you get much shorter life. They are exposed on both sides
to wind and water, and they don't get any heat to dry them
out. Consequently the same bricks used for a garden wall
will have a much shorter life than when used to build a house.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Rod writes:
I did post a few weeks (maybe months now!) ago - a detailed document
form one of the brick making companies. In summary:

Absolutely always frog up - but if some nifty corner or something meeds
to go the other way, fill the frog completely and carefully slide the
brick off the trowel.

Many bricks 'grin' such that if they are laid not frog up, the face of
the brick looks wrong.

Therefore, no saving in mortar.

When I did my bricklay course a few years ago, we were told that
all the major house builders now insist their brikkies use frog
down, as it saves 10% of the mortar. However, the external brick
wall is not structural in modern houses, only having to support
its own weight. The floors and roof all sit on the inner walls.

AIUI, the frog was more to ensure that the brick fired more easily -

That's true.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 30 Aug, 18:56, (Andrew Gabriel) wrote:
In article ,
Rod writes:

I did post a few weeks (maybe months now!) ago - a detailed document
form one of the brick making companies. In summary:

Absolutely always frog up - but if some nifty corner or something meeds
to go the other way, fill the frog completely and carefully slide the
brick off the trowel.

Many bricks 'grin' such that if they are laid not frog up, the face of
the brick looks wrong.

Therefore, no saving in mortar.

When I did my bricklay course a few years ago, we were told that
all the major house builders now insist their brikkies use frog
down, as it saves 10% of the mortar.

Unfortunately, such penny pinching extends to all parts of a new
house.
Thus squeaky floors, wobbly internal walls etc.

However, the external brick
wall is not structural in modern houses, only having to support
its own weight. The floors and roof all sit on the inner walls.

And those inner walls, bizarrely, are made of sponge !

Simon.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember sm_jamieson
saying something like:

However, the external brick
wall is not structural in modern houses, only having to support
its own weight. The floors and roof all sit on the inner walls.

And those inner walls, bizarrely, are made of sponge !

The last few years I've been up the attics of many new-build houses and
I've been taken aback at the sheer cheap 'n nastiness of the
construction of houses that builders are charging an arm and leg for.
It's almost a pleasure to go up into the loft of a traditionally built
house.
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

"Spamlet" wrote in message
...
Bricking being a rare occurrence in my DIY repertoire, I am curious about
the various designs of the bricks. Why do some have holes going right
through, and others just hollow 'frogs' on one side.

My builder bro in law tells me the frogs are supposed to face upwards, but
could not give me the reason why. My 'common sense' view would have been
that, were there to be any missed bits in the mortaring, or should cracks
develop, frogs facing upwards would tend to collect water that might break
up the wall if frozen while still wet. Also, laying 'frogs down' gives me
a flat top to any little bits of bricking I do around the garden - though
'frogs up' would give a better key to any final layer of coping stones, so
that might be the reason I suppose.

What is the reasoning behind frogs, their design and positioning while
laying?

Cheers,

S

Thanks folks, very informative as usual. I had no idea there was so much to
choosing a brick and which way up it goes!

Cheers,

S

On Fri, 29 Aug 2008 17:29:23 +0100, "Dave Plowman (News)"
wrote:

London bricks shouldn't be used for garden walls - they are too
soft and will blow apart within a year or two due to frost / defrost
cycles

I've got lots of ornamental garden brickwork all made out of secondhand
stocks. No problems whatsoever. In over 20 years.

Not all bricks will spall, and your second-hand ones have probably been
selected from ones that didn't.

In article ,
Andy Dingley wrote:
On Fri, 29 Aug 2008 17:29:23 +0100, "Dave Plowman (News)"
wrote:

London bricks shouldn't be used for garden walls - they are too
soft and will blow apart within a year or two due to frost / defrost
cycles

I've got lots of ornamental garden brickwork all made out of secondhand
stocks. No problems whatsoever. In over 20 years.

Not all bricks will spall, and your second-hand ones have probably been
selected from ones that didn't.

Looking at them I doubt they've been selected in any way. Part of the
rustic charm. ;-)

But it's common to have flank walls on houses built with the top bricks
exposed - perhaps 'brick on edge' and they seem to survive ok. Although
mine has stone capping.

--
*That's it! I‘m calling grandma!

Dave Plowman London SW
To e-mail, change noise into sound.

Thanks to all,

Very helpful.

Cheers,

S

replying to Spamlet, Chris wrote:
The frogs should be laid up so that they are filled with mortar when laying
the next course, this improves load bearing capacity. For smaller low load
walls frogs can be laid down to reduce mortar useage.

--
for full context, visit https://www.homeownershub.com/uk-diy...on-503979-.htm

On Wednesday, 17 May 2017 12:44:05 UTC+1, Chris wrote:
replying to Spamlet, Chris wrote:
The frogs should be laid up so that they are filled with mortar when laying
the next course, this improves load bearing capacity. For smaller low load
walls frogs can be laid down to reduce mortar useage.

You're replying to a 2008 post. Get yourself a sane portal to here. Here is news:uk.d-i-y.


NT

Yes and always quote a post if its being reactivated for whatever reason too
as most of us would have not the foggiest idea of why one would bring back
an old thread. Maybe there is a reason but here in the real world onf
newsgroups, we are no wiser.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
wrote in message
...
On Wednesday, 17 May 2017 12:44:05 UTC+1, Chris wrote:
replying to Spamlet, Chris wrote:
The frogs should be laid up so that they are filled with mortar when
laying
the next course, this improves load bearing capacity. For smaller low
load
walls frogs can be laid down to reduce mortar useage.

You're replying to a 2008 post. Get yourself a sane portal to here. Here
is news:uk.d-i-y.


NT

On 17/05/2017 12:44, Chris wrote:
replying to Spamlet, Chris wrote:
The frogs should be laid up so that they are filled with mortar when laying
the next course, this improves load bearing capacity. For smaller low load
walls frogs can be laid down to reduce mortar useage.

This might assist you with posting to a newsgroup, albeit through a website:
https://tools.ietf.org/html/rfc1855

- If you are sending a reply to a message or a posting be sure you
summarize the original at the top of the message, or include just
enough text of the original to give a context.

On 17/05/17 12:44, Chris wrote:
eplying to Spamlet, Chris wrote:
The frogs should be laid up so that they are filled with mortar

I say old chap, that's a bit hard on the frogs. I mean brexit is one
thing, but that's worse than fartynge in theire general direction.

They are building a house next to me. The bricklayer I talk to has a
city and guilds in bricklaying. I asked him, which way up one should lay
the bricks. He said 'doesnt natter really. If we are trying to get a
thick mortar bed to bring the course up to level we lay em frog up
otherwise either way really. The mortar fills the gap whatever when you
tamp the brick down'.

--
"Anyone who believes that the laws of physics are mere social
conventions is invited to try transgressing those conventions from the
windows of my apartment. (I live on the twenty-first floor.) "

Alan Sokal

The Natural Philosopher wrote:

The bricklayer I talk to has a city and guilds in bricklaying. I
asked him, which way up one should lay the bricks. He said 'doesnt
natter really. If we are trying to get a thick mortar bed to bring
the course up to level we lay em frog up otherwise either way really.
The mortar fills the gap whatever when you tamp the brick down'.
Feel free to tell him that owners of any houses he builds with frog-up
party walls won't thank him for it ... though I suspect they'll use
blocks nowadays instead of bricks, and be designed to meet part E noise
requirements, unlike 1970's practices.

Andy Burns wrote:

Feel free to tell him that owners of any houses he builds with frog-up
party walls won't thank him for it ...

Gah! frog-down

On 18/05/2017 06:34, Andy Burns wrote:
The Natural Philosopher wrote:

The bricklayer I talk to has a city and guilds in bricklaying. I
asked him, which way up one should lay the bricks. He said 'doesnt
natter really. If we are trying to get a thick mortar bed to bring
the course up to level we lay em frog up otherwise either way really.
The mortar fills the gap whatever when you tamp the brick down'.
Feel free to tell him that owners of any houses he builds with frog-up
party walls won't thank him for it ... though I suspect they'll use
blocks nowadays instead of bricks, and be designed to meet part E noise
requirements, unlike 1970's practices.

I expect that they will fail noise tests with the frog down as you will
get air voids unless you are really careful. Frog up and they fill with
mortar easily.

On 18/05/2017 06:35, Andy Burns wrote:
Andy Burns wrote:

Feel free to tell him that owners of any houses he builds with frog-up
party walls won't thank him for it ...

Gah! frog-down


That will teach me to post after I read the rest of the thread, or
probably not.

"dennis@home" wrote in message
web.com...

On 18/05/2017 06:35, Andy Burns wrote:
Andy Burns wrote:

Feel free to tell him that owners of any houses he builds with frog-up
party walls won't thank him for it ...

Gah! frog-down


That will teach me to post after I read the rest of the thread, or probably
not.


The Frogs in our pond in the paddock are always 'Frog Up' even when mating,
but this time of year they are making a terrible noise about it, being over
exuberant non natives, as they were introduced here in the 1930's from
Hungary. They've spread to our part of the Brede valley in the past four
years !

When the Heron has one (or several!) for supper they can be 'frog on side'
for a while

http://theromneymarsh.net/amphibians

Andrew