# Old insulation



## msmith5554 (Apr 13, 2012)

I have 30 yr old insul in my attic( blown in ) its black in color and my kitchen contractor called it rock mold insulation. My qs is should I have the old stuff sucked out and new blown in, or just blow new over the top ????


----------



## gregzoll (Dec 25, 2006)

Rock Wool. Most likely the black is just dirt that has transitioned in through the vents, due to air flow. 30 years is not that old, and nothing to worry about. Your best bet is to get a second opinion of a insulating company that has experience in your area, not just some Joe that is doing it, because they lost their job due to the downturn in the economy.


----------



## msmith5554 (Apr 13, 2012)

Thanks Greg. Ya everyone has their own opinion on this matter. One contractor said that the old stuff isn't doing any thing at all and to pull it out. Others have said just go over with new. Hard to know what's the right thing to do ??? You have to ask your self.... What would Mike Holmes do????


----------



## gregzoll (Dec 25, 2006)

30 years old, you move it so that you can air seal any openings from the living space, then put it back, and top it off with new, so that you get the proper R-Value. Also while making sure that there is proper airflow from the soffit vents to the ridge venting. Find the right insulation company that will also do the rebates you will end up making money off of the job vs. losing money.

I have one quote sitting on my table right now, that the cost of the job is around $2800, but after rebates, looking about paying out of pocket about $800.


----------



## Windows on Wash (Aug 30, 2011)

As long as it is not contaminated with vermin feces or urine, it can be moved around (for air sealing as mentioned by Greg) and blown over top.


----------



## M3 Pete (May 10, 2011)

msmith5554 said:


> Thanks Greg. Ya everyone has their own opinion on this matter. One contractor said that the old stuff isn't doing any thing at all and to pull it out. Others have said just go over with new. Hard to know what's the right thing to do ??? You have to ask your self.... What would Mike Holmes do????


Although Mike does good work, he has a seemingly unlimited budget. He'd pull it all out, spray foam it, and put blown in on top of that. That _might_ be a good idea in Canada, with its harsh winters, but it's a substantial upfront investment. 

For the rest of us without unlimited funds, a good air sealing with cans of expanding foam, spread the old insulation back, and top it off with more blown in is the likely answer. gregzoll nailed it.


----------



## Windows on Wash (Aug 30, 2011)

M3 Pete said:


> Although Mike does good work, he has a seemingly unlimited budget. He'd pull it all out, spray foam it, and put blown in on top of that. That _might_ be a good idea in Canada, with its harsh winters, but it's a substantial upfront investment.
> 
> For the rest of us without unlimited funds, a good air sealing with cans of expanding foam, spread the old insulation back, and top it off with more blown in is the likely answer. gregzoll nailed it.


+1

It is easy to do that when you have unlimited budgets as a result of free sub work.

The reality is that you can get 95% of the performance with spot sealing as compared to spray foaming the entire attic floor.


----------



## M3 Pete (May 10, 2011)

Windows on Wash said:


> +1
> 
> It is easy to do that when you have unlimited budgets as a result of free sub work.
> 
> .


Especially when you have a sub that specializes in spray foaming, and is willing to come out for a lot of the small jobs that Mike has. For Mike, it's probably quicker than spot sealing, so it's good for his schedule.

It's a great deal for the subs, they get a load of free advertising (who would not want to hire a guy that Mike Holmes trusts?) in exchange for some free work.

The revenue from the show pays for the Holmes crew. 

We should all be so lucky.

One thing spray foam is good for is to put in a vapor barrier where none exists. But in most places in the US, a vapor barrier is not required (or even recommended). And spray foaming is major dollars compared to other types of insulation.


----------



## Fix'n it (Mar 12, 2012)

M3 Pete said:


> It's a great deal for the subs, they get a load of free advertising (who would not want to hire a guy that Mike Holmes trusts?) in exchange for some free work.


BINGO 




M3 Pete said:


> One thing spray foam is good for is to put in a vapor barrier where none exists. But in most places in the US, a vapor barrier is not required (or even recommended).


thank you for that statement. could you make a recommendation in my "drywall over P&L" thread ? (i don't want to jack this thread) thank you.


----------



## CoconutPete (Jan 22, 2010)

M3 Pete said:


> (who would not want to hire a guy that Mike Holmes trusts?)


Ding Ding! I always chuckle when they show the "insta-insulation" guy pull up in his truck and there's a giant banner on the side that says "official insulation company of Mike Holmes" :jester:


----------

