He knows you know, does Noseall...
- Thread starter Shytalkz
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On form tonight Shy 
Never mind the latte ,more like happy juice
Never mind the latte ,more like happy juice Yep ! he has peaked and gone again after a busy 10 minutes
No no, just doodling in Sketchup! As one does of a Tuesday evening...although I've got shedloads of design work and really should be doing some of that...
Thought Nose was going to ring me about sommat, but he seems to have disappeared
Thought Nose was going to ring me about sommat, but he seems to have disappeared
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I have to be in bed by 9:00 pm.
Here goes anyhow;
Ref: Padstones.
A while back, a building control officer mentioned using cut sections of pcc builders lintel as padstones, i.e. chopping into 450mm lengths and bedding them say 3 courses deep. Job done.
Now a bod at Stafford b.c. is saying that the mortar betwixt is not as hard as the concrete and is a weak spot. How so?
Ok, point loading aside, buildings are built using mortar whether that mortar is at the first course or the last course. The first laid course is taking a lot more weight than the last but is still adequate, no?
The very first course of mortar on a three storey building for instance is going to be bearing a heck of a weight, is it not.......?
...............over to you Shy
Here goes anyhow;
Ref: Padstones.
A while back, a building control officer mentioned using cut sections of pcc builders lintel as padstones, i.e. chopping into 450mm lengths and bedding them say 3 courses deep. Job done.
Now a bod at Stafford b.c. is saying that the mortar betwixt is not as hard as the concrete and is a weak spot. How so?
Ok, point loading aside, buildings are built using mortar whether that mortar is at the first course or the last course. The first laid course is taking a lot more weight than the last but is still adequate, no?
The very first course of mortar on a three storey building for instance is going to be bearing a heck of a weight, is it not.......?
...............over to you Shy
We've just got a new one (BCO) in the forum who would probably say the same thing....
The mortar *is* weaker than the brickwork, true. However, that is taken into account in the codes for the overall wall strength. That's why block walls laid on side take less vertical load than does a normal one of the same thickness, as there's far more mortar in terms of the whole.
Unless there was a mega-marrowfat joint under the pcc lintel, then there would be no significant issue. The same comment could equally be made if the padstone was made out of engineering bricks, has he stopped to think about that?
A cast in place concrete pad would obviously be the strongest of the lot as a) it's all concrete and b) it's cast directly onto the brickwork below. Similarly, a steel plate would be strong too, providing it's of adequate thinckness, and this would sit directly on the wall. But, in either case, below that brickwork is a mortar joint...and so it goes on.
You're quite correct in what you say.
The mortar *is* weaker than the brickwork, true. However, that is taken into account in the codes for the overall wall strength. That's why block walls laid on side take less vertical load than does a normal one of the same thickness, as there's far more mortar in terms of the whole.
Unless there was a mega-marrowfat joint under the pcc lintel, then there would be no significant issue. The same comment could equally be made if the padstone was made out of engineering bricks, has he stopped to think about that?
A cast in place concrete pad would obviously be the strongest of the lot as a) it's all concrete and b) it's cast directly onto the brickwork below. Similarly, a steel plate would be strong too, providing it's of adequate thinckness, and this would sit directly on the wall. But, in either case, below that brickwork is a mortar joint...and so it goes on.
You're quite correct in what you say.
Then you run the risk of having air between! This i DO know is weaker than mortar.
What amuses me is the fact that we are talking domestic scenarios here and not multi-storey.
Shytalkz";p="1159214 said:We've just got a new one (BCO) in the forum who would probably say the same thing....
User name a bit of a give away me thinks
Maybe you should change yours !!!! I know GOD would be your choice
H
hotrod
This thread has reminded me of a question a tutor posed to a class during my first year at Uni. Namely;
Any of you guys hazard a guess at what the tutor was angling at
It wasn't a structural engineering degree before you over analyse the question, but I was the only one to answer correctly.
Any of you guys hazard a guess at what the tutor was angling at
Mortar beds and perp's are there to keep the bricks apart, surely?
Joking apart, does the wall not support the roof, but gain some degree of restraint from the timber elements?
Joking apart, does the wall not support the roof, but gain some degree of restraint from the timber elements?
If there was enough vertical load on a wall to resist lateral loads, then it wouldn't need mortar, because it keeps it in compression. Like an upright flat arch. Take a pile of books off a shelf pressing towards each hand and they dont drop, as it generates friction between the books. Same thing.
But I'm guessing Woody's answer to the actual question posed is the correct one.
But I'm guessing Woody's answer to the actual question posed is the correct one.
H
hotrod
You're right of course nose, I didn't describe the scenario particularly well. Shy described it much more eloquently here:-
Cheers Shy, I knew you would come to the rescue
That's so close. That was my first answer to him! His reply, "Yes technically that is correct, but it's not the answer I'm looking for." So, very warm Woody but not quite.
From memory the discussion went something like this:-
Tutor: Why do we use mortar on brick and blockwork?
Student: Derrrr....stick 'em together innit....duh!
Tutor: In a free standing structure, such as a garden wall, yes a mortar bond is imperative to structural stability. However, given that bricks and blocks are modular and assuming adequate vertical loads from the structure above, the bricks/blocks will be in compression and therefore resist any lateral loads. Therefore, why incorporate mortar beds when constructing in traditional masonry?
Anyone hazard a guess as to what the tutor was alluding to
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