How wide can joints be in mortar for dwarf wall greenhouse

[Eamman]

Trial and error, or experience I'm afraid -depends on the weather, the bricks, how quickly you lay them etc. I usually find wetter is better (but not slopping off your trowel or all over the faces of the bricks) - gives you a bit more scope for adjustment. And although you shouldn't, for what you're building you can get away with mixing in a bit more water if it starts going off.

What about adding more cement if it's too wet? Bad idea?

 

[Eamman]

You'd be far better as a first timer just cutting a few bricks, you won't need to worry about the joint size, just get them fairly even - measure the first at 10mm and refer back as a visual guide for the rest.
I've cut the bricks on one side of my extension - it makes it easier because any difference along the course in joint/brick size can be taken up by slightly different sized cuts, most are between 17-18cm:
View attachment 198980

The other wall is exact bricks length - but I'm always a few mm over or under at the end so it's messing about pushing/pulling the last half a dozen to get them looking ok.

For a course of 20 bricks you should really work to a line, it's as simple as this:
View attachment 198981

Set the first brick, transfer the level to the last brick on the other end (spirit level on a straight edge, depending on length you'll probably have to do it in two goes), pull a taut line between the two and off you go.
The proper way to do the beds is to draw the point of the trowel down the middle, cut the excess off the side, butter up your ends etc like on YouTube but you're not a bricky so just get it on however you can and work to the line (as close as you can with the top front of the brick without touching it) - push the brick on firmly, if it's low take it off and add some more mortar, if it's high you can try and tap it down a LITTLE bit with a hammer, otherwise take a bit of mortar out. Don't worry about bits with missing mortar, you'll fill those in when you joint up at the end - just focus on getting that course of bricks on, keep working the mortar and mix in small batches as it'll be going off at the speed you'll be working at.

Probably unfair to ask but you say a 4 to 1 mix above in that bucket do know how much water you used for that? Also should I level bricks lengthways and widthways?

 

[cdbe]

If it's too wet and more sand/cement at 4:1. The water depends on how wet the sand is, you want something where if you pick up a trowel full it will settle on it but not drip off.

Working to a line will get the bricks level lengthways, front to back you want the face vertical, not the top level, however if the bricks are uniform this should be one and the same. My brother in-law built his entire garage by leveling each brick front to back, despite my dad (retired bricklayer) telling him he didn't need to, but it worked for him, and if it helps your confidence go for it.
There's loads you will quickly pick up as you go, for example if you tap one end of a brick down the other end will rise up - you need to aim for just past the middle, you'll soon know when your mortar is getting unworkable and needs livening up - because you won't be able to work with it!

 

[Eamman]

If it's too wet and more sand/cement at 4:1. The water depends on how wet the sand is, you want something where if you pick up a trowel full it will settle on it but not drip off.

Working to a line will get the bricks level lengthways, front to back you want the face vertical, not the top level, however if the bricks are uniform this should be one and the same. My brother in-law built his entire garage by leveling each brick front to back, despite my dad (retired bricklayer) telling him he didn't need to, but it worked for him, and if it helps your confidence go for it.
There's loads you will quickly pick up as you go, for example if you tap one end of a brick down the other end will rise up - you need to aim for just past the middle, you'll soon know when your mortar is getting unworkable and needs livening up - because you won't be able to work with it!

What I meant is wouldn't the added cement dry out the sand a bit and make it better? By the face you mean the side facing out that one sees? I thought one would at least need the corner bricks level each way, everything refers to those bricks?

 

[Eamman]

If it's too wet and more sand/cement at 4:1. The water depends on how wet the sand is, you want something where if you pick up a trowel full it will settle on it but not drip off.

Working to a line will get the bricks level lengthways, front to back you want the face vertical, not the top level, however if the bricks are uniform this should be one and the same. My brother in-law built his entire garage by leveling each brick front to back, despite my dad (retired bricklayer) telling him he didn't need to, but it worked for him, and if it helps your confidence go for it.
There's loads you will quickly pick up as you go, for example if you tap one end of a brick down the other end will rise up - you need to aim for just past the middle, you'll soon know when your mortar is getting unworkable and needs livening up - because you won't be able to work with it!

What do you mean by past the middle? how do you liven up the mortar?

 

[cdbe]

If you add just cement (in large quantities) you will change the ratio of the mix.

Level the corner bricks.

If you tap the brick just past the middle towards the end that needs to go down then the whole brick will go down, hopefully more at the high end, if you tap right at the end the opposite end will seesaw up.

Liven it up by mixing it a bit - that's what they're doing on YouTube when they throw it around their boards.

I suggest you move on from the theory to the practical stage now! Things may become a lot clearer.

Don't forget plasticiser and to post some pictures!

 

[Eamman]

If you add just cement (in large quantities) you will change the ratio of the mix.

Level the corner bricks.

If you tap the brick just past the middle towards the end that needs to go down then the whole brick will go down, hopefully more at the high end, if you tap right at the end the opposite end will seesaw up.

Liven it up by mixing it a bit - that's what they're doing on YouTube when they throw it around their boards.

I suggest you move on from the theory to the practical stage now! Things may become a lot clearer.

Don't forget plasticiser and to post some pictures!

 

[Eamman]

I'm finding parts of the foundation are not level by 20mm or there abouts! This means some bricks are sitting on 20mm of mortar, is this too much on the base?

 

[sircerebus666]

No that's fine , just make sure your first course is spot on level wise

 

[Eamman]

No that's fine , just make sure your first course is spot on level wise

So far so good, have one long side completed and half a short side! All levels far!

 

[stuart45]

Well done.
Don't forget to stick some photos on.

 

[Eamman]

I'm taking the scenic route doing one brick at a time, and getting it level lengthways and sideways!

 

[Eamman]

Here's a question for you,is there a safe time to lay bricks before expected rain comes, for instance, the day before 2 days before, or should one wait for reasonably dry weather?

 

[kingandy2nd]

Just make sure it’s covered up once laid any you’ll be fine.

 

[Eamman]

Just make sure it’s covered up once laid any you’ll be fine.

How 'dry' can they be before rain affects the fresh mortar?