closing off damper on wood insert

[bdaber01]

Sorry if this has already been answered (direct me to the thread if it has), but im about to finish installation of my napoleon 1401 insert and the manual calls for using 26 gauge sheet metal to cover up the opening where the flex liner came thru the damper. I was wondering if this step is critical, or if i can get away with leaving it open. The stove doesnt require i use the flex liner, so if i were to vent directly thru the chimney i wouldnt need to cover up the opening in the damper. Anyways, this is the second to last step i need to carry out and was wondering if it was necessary. Also if it is, anyone know if home depot or lowes carries that gauge sheet metal. i know the sheets for regular HVAC are only 30 gauge.

thanks...

 

[nshif]

This is called a block off plate and is highly recomended. One thing it does is keep most ot your heat from going up the chimney. Do a search for block off plate on this site or there is an article in the wiki
pretaining to building and installing one.

 

[elkimmeg]

I have a few questions first what size clay liner are you trying to vent into? did you know that once you pass the damper block off plate the pipe has to be corrosion resistant
meaning stainless steel. much of good HVAC, should be 26 gage which will work fine to make up your damper block off If I find 30 gage used it usually fails inspections and gets removed

from all of you descriptions of you final stage of the installation I gather you have not pulled a permit for this work. I really think you need a bit more education in what you are doing

Welcome aboard the Hearth I'm sure others will be along to help you make wise and safe decisions

 

[budman]

Sorry if this has already been answered (direct me to the thread if it has), but im about to finish installation of my napoleon 1401 insert and the manual calls for using 26 gauge sheet metal to cover up the opening where the flex liner came thru the damper. I was wondering if this step is critical, or if i can get away with leaving it open. The stove doesnt require i use the flex liner, so if i were to vent directly thru the chimney i wouldnt need to cover up the opening in the damper. Anyways, this is the second to last step i need to carry out and was wondering if it was necessary. Also if it is, anyone know if home depot or lowes carries that gauge sheet metal. i know the sheets for regular HVAC are only 30 gauge.

thanks...

Is this liner going all the way to the top of chimney with top plate.Also is this chimney
on the inside of house or an outside wall.

 

[kd460]

Yes, do a search on block off plate. Go to a local metal supply house and get a piece of stainless in the gauge elk has stated. I know stainless is not necessary, but, isn't all that expensive. A little kaowool insulation above the plate won't hurt either. Just don't use fiberglass insulation.

Do your homework before you install. No sense in pulling things out later or put your family at jeopardy. Search, read, and search and read some more. The info is here. Do it right the first time.

You should be using stainless liner (flex or rigid) that is made for your stove, that runs from stove (insert) to the top of the chimney, as well as insulating the liner. A top block off plate is needed as well (at the top of chimney) and a proper cap. Clean the old chimney and smoke shelf first, before anything else. The stove does not require a flex liner, but local code probably does. The flex liner manufacturer probably will require insulation to the liner as well. If you don't go with a flex liner, then you will need to pull the insert every time you clean the chimney (something that should be done regularly) and pulling the insert will be a hassle. Other safety factors exist with not using a full length liner as well as other hassle factors.

Your insert will work much better with the liner, and a much safer install as well. KD

 

[budman]

Yes, do a search on block off plate. Go to a local metal supply house and get a piece of stainless in the gauge elk has stated. I know stainless is not necessary, but, isn't all that expensive. A little kaowool insulation above the plate won't hurt either. Just don't use fiberglass insulation.

Do your homework before you install. No sense in pulling things out later or put your family at jeopardy. Search, read, and search and read some more. The info is here. Do it right the first time.

You should be using stainless liner (flex or rigid) that is made for your stove, that runs from stove (insert) to the top of the chimney, as well as insulating the liner. A top block off plate is needed as well (at the top of chimney) and a proper cap. Clean the old chimney and smoke shelf first, before anything else. The stove does not require a flex liner, but local code probably does. The flex liner manufacturer probably will require insulation to the liner as well. If you don't go with a flex liner, then you will need to pull the insert every time you clean the chimney (something that should be done regularly) and pulling the insert will be a hassle. Other safety factors exist with not using a full length liner as well as other hassle factors.

Your insert will work much better with the liner, and a much safer install as well. KD

Well said KD. ;-P

 

[kd460]

Budman, took me awhile but I got it

 

[bdaber01]

thanks for all of the responses. I will try to answer each of the questions but forgive me if i miss any. The Chimney is on the outside of the house and two stories (about 23 linear feet from top of stove to to of the flue. The flue is about 9 inches by 9 inches and ive swept and inspected, and its in pretty good condition. I have obtained a permit for the job, but the town does not require me to install a chimney liner, i was just going to do it since its recommended by the stove manufacturer and it will be easier to keep clean. I purchase a 6 inch stainless steel flex liner kit including top plate and rain cap, ive installed all of that and have the flex liner thru the opening where i removed the damper. I needed to install a low clearance flue adapter since i couldn't get the flex liner to drop right on top of the stove.

I appreciate all the help....i've found some great web sites describing how to construct the block off plate....(i tried searching the past few days i its amazing how you can find something so quick once you know what its called...thanks)....Ive checked home depot again and all they carry is either 26 or 30 gauge sheets of galvanized steel (the 26 gauge is just too small of a sheet though). Based on your suggestions ill stay away from the 30 gauge and go to the local supply shop for the right stuff.


Thanks again and i'm sure ill be back with more questions as the once the burning season begins....

 

[bdaber01]

as for insulating above the block off plate, can i pick up kaowool or an equivalent at a local home depot or lowes?

 

[kd460]

No to the kaowool at home depot. Look up refractory or kiln supplies in the phone book, or if you have to ebay. You don't need much, just think about how you would seal things up and insulate while your installing the plate and add the insulation and stove joint sealing compound as needed. The stainless, along with stainless screws just seems to make sense to me.

If you insulated your liner, then you can use the leftover stuff from that. If you did not insulate the liner, then you are missing out. Especially with a chimney on an outside wall. I did not insulate my liner, and while my insert worked OK with no real problems, I should have, and ended up pulling my liner to insulate it a month or two ago. Man what a difference. Start ups are easier and faster, no problems with having to "warm up the flu" with newspaper (so far), and the draw is so much better. While it isn't really cold yet here in Michigan, I can tell the insert is working better, as my damper settings are different from last year telling me the insert draws better.

As mentioned earlier, you may need the insulation to meet the ul listing/rating, or for longevity of the liner, and/or the manufacturer of your liner may require it. As far as pulling it and insulating it this year? The answer I got last year was basically, "wait and see, if problems, then insulate". But looking back, I am glad I did.

As far as block off plate construction, pick up a cheapee Harbor freight 4 1/2 angle grinder like this one:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91223

And a couple of cut off wheels and flap discs. Now you can cut your sheet metal without distortion, and smooth out the cuts with the flap disc. While a cheap tool, it is handy and you will find yourself using it more and more often. Works good at cutting the hole, just go slow and make small cuts. KD

 

[bdaber01]

thanks a ton, was planning on going a season without insulating my liner since i spoke with some guys at a local shop when i first started looking for an insert and they told me i wouldnt need it. I dont know if they were just trying to make a deal, but he actually told me that not insulating it would give me better draft airflow to pull the warm air thru my house. So i went cheap and purchased the liner online and skipped on the insulation. After your advice i might as well just pull it now before i finish the job and insulate. It wont be hard to pull back out since i have plenty of clearance thru the chimney flue. thanks again for the advice

B

 

[gpcollen1]

I do not think that an insulated liner makes much of a difference, especially if you are operating 24/7. Last year I lit my stove off maybe 3 times. I have nothing against those with insulated liners, just if you have an intact chimey in good condition, no real need to insulate the liner.

 

[MrGriz]

Especially if your liner is in already, I would give it a try without the insulation this year. I have 23' of uninsulated liner in my exterior chimney and my insert drafts very well. I don't have any issues with starting a fire and having to warm the chimney to induce draft.

While I agree that this set up has a higher potential for problems, it seems to be situational. I would give it a try before going through the trouble and expense of removing the liner to insulate.

 

[bdaber01]

Well the block off plate is in, ive insulated above it with some kaowool....

I do need some advice on a problem i have encountered with attaching my flex liner to the flue adapter coming off the stove. My liner did not line up with the stove collar so i purchased a low clearance flue adapter from the stove supply shop that puts the flue collar at a 45 degree angle to receive the liner which drops in from the closed off damper at an angle as well. As it turns out the angles are not perfectly matched up so i cant get the liner to slip nicely into the flue adapter. The bottom part of the liner sits in the adapter opening by about an inch while the top part of the liner sits just in the mouth of the adapter. The gap is very small but i can see light when i put my flashlight into the firebox. The adapter attaches to the liner using a hose clamp about an inch and a half away from where the liner and adapter pipes meet. (http://www.chimneylinerdepot.com/store/comersus_viewItem.asp?idProduct=65) so i can get the liner to stay in place just fine. I spent some time looking around on different forum posts and most of the sealing is done with furnace cement ( have plenty left over from sealing off the liner and close off plate gaps). How far into the receiving adapter must the chimney liner be for the furnace cement to do a good job sealing off the gap? How well does the furnace cement (Rutland) hold to up the expansion/contraction of the pipes during usage cycles?

If my description of the setup is too vague or confusing let me know, ill try and do a better job.

 

[elkimmeg]

Before you cement anything what about returning the offset adapter? Ventnox or Homesaver make an adjustable off set adapter

looks like this

 

[bdaber01]

I have done the measurements and that offset adapter wont work for me since the flex liner is coming into the firebox thru the damper on an pretty heavy angle. The ceiling height of the firebox is too low to allow me to get a decent bend in the flex pipe after it enters the box to get the liner to be perpendicular to the ground and thus line up with the adapter you mentioned. . If my insert was about 6 inches lower i would be able to get away with that type of offset adapter. The one i have in there lets me enter the insert at about 45 degrees, but even then im about 5-10 degrees off with the liner and unless i take more off of the firebrick above the insert i wont ever get the liner and adapter to line up.

How deep into the adapter does the liner need to protrude? if its enters on one side by about an inch and a half and the top side by only about an 1/8-1/4 inch inside is that enough to allow me to clamp off the liner and just seal up the connection with furnace cement?

im guessing the furnace cement is fairly permanent and thats why i should use it as a last resort?

thanks

 

[BrotherBart]

I will let others advise on sealing that gap. I wouldn't do it because furnace cement isn't as "permanent" as usually believed. Brushing the chimney can chip away at it. I had the same angle situation installing my stove into the fireplace and solved it by using a fixed 30 degree stainless steel elbow that has a clamp setup to hold the liner like you have on the appliance adapter. It was a cleaner install and only costs forty dollars. I refuse to use offset adapters because they are a nightmare to clean whereas with the elbow you can just pull the brush straight down the liner through the elbow and into the firebox. That and the exhaust gases don't have to make any fancy turns before heading for the sky.

I understand some people use adapters like this. UL approved but for electricity, not smoke.

 

[bdaber01]

well i ended up loosening up the connection between the low clearance flue adapter and the stove itself, this let me slide the liner deeper into the adapter before tightening the hose clamp. the connection was much more secure and when i tested the fitting with a flashlight, there were literally only two pinholes at the seam allowing light thru, so i just applied a very little amount of silicate cement sealent and that took care of that. As for the adapter, i was able to get it to attach to the stove as it was prior to loosening it up. There were a few spots along its seal to the stove that allowed light to pass thru, so i sealed those positions with the same sealent (rutland). No light passing thru any connections at this point, final inspection is today so ill see how well things go.

Thanks for the input from everyone.

My last questions is with regards to a surface thermometer. Anyone have any good suggestions for an accurate thermometer? Also anyone have a napoleon 1401 and know where the best spot to place the thermometer at?