Rigid vs Flex...installation comparison for my situation.

[Lasher]

I have searched and read about 30 pages of topics for installation and whatnot. But I am still not sure on which way to go. I understand that rigid is better than flex, for draft, longevity, cleaning and safety. But I am a little nervous about installing the rigid pipes in my chimney.

I need to take exact measurements of length, but here is the rough picture:
Chimney is new (2002 built house) and in great shape.
External chimney entire length.
About 35 feet tall from ground, bottom of fireplace to chimney is about 30 feet. I will get exact measurements this weekend. (lost tape measure)
Flue is 13x13
The flue is offset about 1 foot from center of fireplace and straight shot. If I look up from fireplace 1 foot to the right of center, I can see sky.

My optimal plan would be to put insulated rigid from the the top of the chimney to bottom of the flue. Then use flex to connect to the insert. But I am a little nervous about installing the rigid liner. Talking it over with my father (who will be helping me on the installation) I wonder how rigid is actually installed.

From what I have researched my optimal plan would be in the following steps.

1) Connect flex bottom piece to first rigid section.
2) Climb ladder to top of chimney.
3) Raise flex/rigid liner connection to chimney top using rope.
4) Insert flex/rigid liner into chimney.
5) Somehow support liner in flue? See below for my thoughts/options...
6) Raise next piece of rigid liner to chimney using rope.
7) Connect male/female ends of rigid liner then pop rivet together.
8) Lower connected pieces into flue.
9) Raise next rigid section and repeat until all rigid pieces are in place.
10) Connect top plate to rigid liner and install cap/rain guard etc.
11) Cut off excess flex liner and connect to insert.
12) Start a fire and enjoy!

Now my biggest concern is how to support the liner as I working. I will be the only one on the ladder, and my roof is too steep to have a second person up there. I do not see a big issue with doing the work from the ladder, but I cannot think of an easy way to support the liner while I am getting the next piece up top and connected. Any ideas? Is there some tool that I could use?

At first I was thinking of using something from the bottom to hold it up, but then I realized that I needed to attach the flex bottom section before. I suppose a second person could support the liners once it reaches into the fireplace, but the initial pieces would still need some support. Then I thought about putting a rope thru the flex/rigid tied to a circle piece of wood at the bottom, rope threaded up inside the flex/rigid and securing the rope at the top. But then I need to thread the rope thru each piece as I attach them. I cannot think of a way to secure from the top the installed pieces. My father has some wood working clamps, I thought maybe I could use those to clamp to the liner and it is long enough to rest on the top of the flue. That might work...

Option A is to run flex liner from the bottom up to the top. I can see how bringing 30 feet of felx liner + insulation up the ladder and pushing it down might be a little hairy on the ladder.
Option B would be buy smaller sections of flex and running it from the bottom up to the top. But I think that will be more work if not impossible.
Option C would be to rent a platform lift and have two people up there. I am going to look into how much one would cost.

So...how do people support the rigid liners? Or is this a two man job up top?

 

[tradergordo]

For lining an existing chimney, I'd go with the one piece flex pipe. I've helped with two of these installs before, its mostly a one person job on the ladder/roof, but it helps to have another person inside to yell when the liner is all the way down, and to pull it out of the chimney from the bottom. In both cases, it was from the top down. Lugging the liner up the ladder and stuffing it down the chimney wasn't that bad.

 

[theheatelement]

Like trader says for your installation flex might be the better system... Just throw it down your system hook it up and be done with it..

For lining an existing chimney, I'd go with the one piece flex pipe. I've helped with two of these installs before, its mostly a one person job on the ladder/roof, but it helps to have another person inside to yell when the liner is all the way down, and to pull it out of the chimney from the bottom. In both cases, it was from the top down. Lugging the liner up the ladder and stuffing it down the chimney wasn't that bad.

 

[webbie]

Flex is easier, but as you mention that is perhaps the only thing going for it. It is not as straight, has rough walls, is thinner, etc.

I'm not saying that it isn't adequate. We have installed a lot of flex with few problems...and if you don't feel comfortable doing the rigid, that is an important issue.

We would usually:
1. Attach a 6-8 foot piece of flex to the bottom of a 4 ft (or longer) piece of rigid. If needed, the bottom end would be slightly oval to get through the damper.

The drop it down and connect additional pieces - to save time and energy, 2 4ft pieces can be joined before you start, so this makes 8 ft sections. You are probably talking about 3 of these plus your flex, so it is not very many!

As to supporting it while dropping, there are various ways including:
1. Two people on the roof, one holding and one attaching. You can use rope of some sort, or if pipe is light enough, person can easily hold up as you go.
2. Use some sort of clamp around the pipe, for instance a simple hose clamp, and drop the pipe down through a plate with a hole in it that the pipe slides through, but not the hose clamp on the pipe - you can get fancier and secure the hose clamp to 2 small angles (heavy sheet metal or angle aluminum, etc) which are larger than the tile.

Given the steep roof, you would have to use the clamp method of some sort. Easier than it sounds. Done right, the pipe will still need slightly pushed down as you go....and then you tighten the clamp a bit and attach the next piece. Given your height, you are talking about less than the 3 8 footers, considering maybe 6 feet of flex on the bottom or even 5 feet (this is a standard length for the old direct connects). When the job is done, the pipe can be supported by a clamping top plate or a top plate with a collar (screws or rivets) - the flex at the bottom will make up for expansion and contraction.

Heat-fab and others many have some manuals on their site, but this is how I remember doing it. Remember, the entire assembly in this case probably weighs less than 60 lbs...

 

[Hogwildz]

Lasher,
you have a pm. Either way will work. Your installing about 27' of liner from insert top to a foot or so above the top of old chimney. Exactly what I did.
I personally went with the system you just described. I would do it all over again in a second. You have an outside chimney, it should be insulated. I chose the rigid down to flex because no additional insulating needed. rigid is already insulated and flex where its at needs no insulation. I found for not a whole heck of alot more, I could do it this way, rather than a long flex and then buying & wrapping the insulation around the flex. You have a 13x13 which is about 11x11 inside , plenty of room with no worries of getting either rigid or flex stuck. Its a matter of preference. I do know the rigid is much easier to clean than the flex. And the flex is smooth, no ridges to collect buildup, creosote etc. And also more aerodynamic flow wise, and less resistance with a smooth wall surface. I am sure either way is fine. Not knocking flex.
For me, the ease of cleaning is worth the extra cash & effort. And the rigid is obviously more sturdier than the flex. Do it how you want to do it. That way there is no regrets or second guessing in the future.


PS. You don't necessarily have to cut the flex at bottom if you go rigid. I ran 5' flex, 5- 4' double wall, 1-2' double wall. Ended up with about 18" out the old flue tile at top.
Perfect, and could have gone up a bit or down a bit and still been fine.

Web is close to target for weight. Each 4' pc of double wall 6" DuarLiner is 12 lbs.Mine all totaled was prolly about 83 lbs, pipe & flex. I was a lil off on the guestimate I gave you in PM. The pallet must have been heavier than I thought. Everything comes shrink wrapped on a pallet. It does seem heavier when you have limited footing and limited grasp up there.