How do I work on the top of this chimney?

[fire_man]

Yes this is going to be a warm weather job.

I seem to remember the type N mortar is the "softer" and less structurally strong mix. I never heard of adding acrylic modifier, I'm guessing it makes it more water resistant?

What problem does too hard type S cause?

 

[Seasoned Oak]

You dont want it to hard. That will cause worse problems down the road. We typically use type n with an acrylic modifier for pointing work. Type s if it is a really hard brick and softer for soft brick. Occasionally even lime mortar.

We used what was recommended by the flue and block supplier ,may have been type S,id have to look at the bag. I have to do about a foot of the top of a 12" flued masonry chimney this spring and ill be using the same stuff. Whatever was in there before fell out like dry sand ,the bricks are about to fall out.

 

[bholler]

We used what was recommended by the flue and block supplier ,may have been type S,id have to look at the bag.

Then it should be fine but you should not have used the same mortar for both. You need refractory cement for the clay

 

[bholler]

We used what was recommended by the flue and block supplier ,may have been type S,id have to look at the bag.

But laying a block chimney is very different from repointing an older brick one.

 

[bholler]

Yes this is going to be a warm weather job.

I seem to remember the type N mortar is the "softer" and less structurally strong mix. I never heard of adding acrylic modifier, I'm guessing it makes it more water resistant?

What problem does too hard type S cause?

Acrylic modifier makes it bond better if your mortar is harder than your brick if things move your brick is what is going to give not the mortar. And that is much harder to fix. You always want your mortar a little softer than your brick.

 

[Seasoned Oak]

Then it should be fine but you should not have used the same mortar for both. You need refractory cement for the clay

Yea we did use the refractory cement for the clay.

 

[bholler]

Yea we did use the refractory cement for the clay.

Good

 

[bholler]

The modifier also makes the mlrtar much nicer to work with. It is smother and stickier.

 

[patrickoneal]

Your chimney looks more accessible than mine. I ended up getting a tow behind man lift from the rental house to install my liner. I would have died trying to do it from a ladder. Always get a taller lift than you think you'll need, if you have to go up and over anything, the maximum height is diminished quickly.

 

[LondonNeil]

A scaffold will definitely make the job safer, swifter, less awkward, less painful and more pleasant all round, but it could be done ok on a ladder. I'd suggest you get a ladder out and get up there for a closer look before you for
Hire the scaffold, just to inspect and determine how big the job is. Is it just the one corner that needs re laying or is it most of several rows? How is the flaunching? Just how much needs repointing? Maybe take a trowel or chisel and have a prod/rake at the loose pointing to get an idea of how hard it is to clean a bit out. Then you'll have a better idea if the scaffold is needed for a weekend, a week or longer, and you'll know what other materials you need.

 

[VirginiaIron]

I wouldn't tie into the roof unless you absolutely must. If your siding is vinyl and that is easy to R&R, silicone and ensures it is rain tight.

Sorry, A clearer display indicates it isn't vynil

 

[fire_man]

A scaffold will definitely make the job safer, swifter, less awkward, less painful and more pleasant all round, but it could be done ok on a ladder. I'd suggest you get a ladder out and get up there for a closer look before you for
Hire the scaffold, just to inspect and determine how big the job is. Is it just the one corner that needs re laying or is it most of several rows? How is the flaunching? Just how much needs repointing? Maybe take a trowel or chisel and have a prod/rake at the loose pointing to get an idea of how hard it is to clean a bit out. Then you'll have a better idea if the scaffold is needed for a weekend, a week or longer, and you'll know what other materials you need.

Its at least one row of brick on one side as shown in the picture and also the corner. I'm sure it would be a week of needing the scaffolding since as bholler says I need a better crown. If it was much worse i would definitely go with scaffolding but there is just not that much there to repair. I'm gonna talk to the scaffolding rental place and get a better idea what's involved.

 

[fire_man]

I wouldn't tie into the roof unless you absolutely must. If your siding is vinyl and that is easy to R&R, silicone and ensures it is rain tight.

Sorry, A clearer display indicates it isn't vynil

Agreed - I really don't want to punch holes into the roof. The siding is cedar. I think I would strap the scaffolding to the chimney.

 

[fire_man]

Your chimney looks more accessible than mine. I ended up getting a tow behind man lift from the rental house to install my liner. I would have died trying to do it from a ladder. Always get a taller lift than you think you'll need, if you have to go up and over anything, the maximum height is diminished quickly.

View attachment 218365

How pricy was the lift rental? I don't have good access from the driveway so I'm guessing that would not work.

 

[VirginiaIron]

Just a thought. You could make a sandwich type clamp to brace from an open window and sill on each side of the chimney. Make sure the scafold rests against the masonry that abutts the wall and then you could use 2x4s to to the ground to wedge the scaffolding toward the masonry. No holes drilled in the structure.

 

[VirginiaIron]

How pricy was the lift rental? I don't have good access from the driveway so I'm guessing that would not work.

If the ground isn't level you might have problems with it cutting off to prevent tipping. Then you'd have to find a way to climb down

 

[fire_man]

Just a thought. You could make a sandwich type clamp to brace from an open window and sill on each side of the chimney. Make sure the scafold rests against the masonry that abutts the wall and then you could use 2x4s to to the ground to wedge the scaffolding toward the masonry. No holes drilled in the structure.

Interesting idea to use the windows for clamping.

 

[bholler]

Guys a couple screw holes in a shingle roof will be just fine. When you pull them out just caulk the holes with urethane caulk then rub some of the grit onto it out of the gutter on them. You will never see them and they will never leak.

 

[bholler]

I really prefer scaffold over a lift for masonry. You run out of room and weight capacity pretty quick in that basket

 

[fire_man]

Yea I think the scaffolding is the right way to go. I have plenty time to plan all this out - its 23F out and it does not get really cold till next week!

 

[fire_man]

How do you build a proper frame to pour the crown? Is it 2x6's framed around the top brick but how do you get the overhang?

 

[bholler]

How do you build a proper frame to pour the crown? Is it 2x6's framed around the top brick but how do you get the overhang?

2x4 around the top of the chimney then 2x8 outside that that will give you 1.5" overhang. I would also take the top course that steps in off it will look much better and be more water tight.

 

[patrickoneal]

How pricy was the lift rental? I don't have good access from the driveway so I'm guessing that would not work.

I rent a lot of equipment at work, so I get a really good price on occasional rentals for personal use. Sunbelt Rentals and United Rentals both list prices online, and may be able to beat the listed price.

This is the lift I used:

https://www.jlg.com/en/equipment/towable-boom-lifts/tow-pro/t500j

My driveway is fairly flat, but all that lift needs is a solid surface(pavement, gravel, dirt, grass) up to 11 degrees out of level. Before the boom will operate you hold down a button that deploys all 4 outriggers and it lifts the wheels off the ground and automatically levels the machine.

Edit: I just checked Sunbelt's site, and the list price is $325 for a day for a tow behind 50' lift. A lot of these places will let you pick up equipment late on a Friday and return it first thing Monday morning and only charge for one day. I think even Home Depot rents these things out now, but probably isn't as friendly with the weekend discounts.

 

[fire_man]

2x4 around the top of the chimney then 2x8 outside that that will give you 1.5" overhang. I would also take the top course that steps in off it will look much better and be more water tight.

I like the idea of removing a course of brick since maybe then I might not have to add to the clay liner. But what's supporting the old crown and if I remove the top course what happens to that support?

 

[fire_man]

I rent a lot of equipment at work, so I get a really good price on occasional rentals for personal use. Sunbelt Rentals and United Rentals both list prices online, and may be able to beat the listed price.

This is the lift I used:

https://www.jlg.com/en/equipment/towable-boom-lifts/tow-pro/t500j

My driveway is fairly flat, but all that lift needs is a solid surface(pavement, gravel, dirt, grass) up to 11 degrees out of level. Before the boom will operate you hold down a button that deploys all 4 outriggers and it lifts the wheels off the ground and automatically levels the machine.

Edit: I just checked Sunbelt's site, and the list price is $325 for a day for a tow behind 50' lift. A lot of these places will let you pick up equipment late on a Friday and return it first thing Monday morning and only charge for one day. I think even Home Depot rents these things out now, but probably isn't as friendly with the weekend discounts.

We have a lift dealer about 4 miles away but this job is definitely a 3 day job - especially with the crown. Someone like bholler could probably do it in a day so that would mean at least a week for me!