Lintels - Catnic versus concrete

[Ted]

I have never used a steel lintel when putting a lintel in above a door and have only ever used pre-stressed concrete ones.

Mind you, I have not fitted many lintels above doors in my past jobs to date.

However, I am taking over a job where all the lintels that have been fitted (bar one) are Catnic ones. They are very expensive, these Catnic lintels.

Can someone explain why, where and when you use a Catnic lintel. It seems that hundreds of pounds have been spend on Catnic lintels when concrete ones would have sufficed.

Also, do you not need padstones with Catnic lintels? I have always used padstones but this builder who has done the work to date has not used any.

[lutonlagerlout]

ted people use catnics because they are light and easy to handle
unless they are heavy duty they do not need a padstone
i always use concrete inside i.e. where plastered.
i think some jobs just specify catnics or IGs so the architect looks more profesional
cheers mate
LLL

[Ted]

In this case the arch may think it makes him look more of a pro but he is spunking a client's cash unnecessairly IMHO... further negligence if you ask me!!!

He has specified a Catnic to support one course of thermalites in several areas....

[lutonlagerlout]

ahh wait a minute
you are not suppose to use a concrete lintel unless there is at leats 450 mm of masonry on it or loading
because they are pre-stressed apparently they are not as strong if they have little or no loading on them
1 course of thermalites is not heavy IMHO
cheers LLL

[Ted]

Interesting...

The arch seems to have a few things up his sleeve to prove his integrity... I may be wrong but there are too many suspect goings on IMHO...

He bangs on about his schoolboy career at Oundle; IMHO anyone, particularly at the age of 66, who trumpets their public school credentials as some sort of proof of their integrity is serioulsly lacking and suspect...

[Ted]

I have now found places where the builder has used concrete lintels where the arch has specified Catnic... the arch never said concrete was OK!

When using concrete lintels is it OK not to use a padstone in some cases?

[lutonlagerlout]

IME ted you don't need padstones for concrete lintels,padstones are only used for steelwork where they increase the crushing strength of the wall by a factor of at least 2
with the prestressed I'm sure you need a good bit of weight on it to work properly
cheers LLL

[Ted]

The builder who I learnt what I know off always used padstones.

It may well be OK and there doesn't seem to be much up the lintel avenue in my dispute, but it just annoys me as the builder who taught me would probably have had the whole job done for the price the client has paid and it would be a quality job too...

This case also makes me wonder what use architects are!