Insulation of a Porch - how to

[Nel frattempo]

The children and I built a porch and now want to enclose it to make a large mud room / laundry room. Since I want to move the washing machine and a sink out there, it will need to be insulated. We know how to do the walls, ceiling but I am wondering what I can do underneath. We store things ( kayaks / water tubs / luggage rack / tents ) up under there so I did not want to "under pin" it but may have to.......

Would it work to put the pink puffy insulation up under the floor, then seal up the under the floor with the solid insulation? That would put the water pipes up in the insulation........or is that not enough? Our drain line goes out to a gray water system and I don't think that would freeze up since the fall is so steep there would be no water holding in the line?

Or do I just need to go on and put some type under pinning around the whole bottom?

Thank you

[Old Vet]

There are ,many ways to insulate the floour. The best way is to put fiber glass insutation in the cover it with a black board or plastic (black and the heavest you can get). Undrer ping it will only stop the breese from going under their. If you use plastic wise some laths to hold it up.

[wy_white_wolf]

Have it urethane spray foamed.

[Nel frattempo]

We need to do the work ourselves .....so the spray foam would not be an option. Sounds like pink insulation / then black tar paper? Or would the solid foam type be best tacked over the pink stuff?

[Hooligan]

+1 For the spray in insulation although it is expensive around here.

In my nothern climate it would not be a good idea to put a vapor barrier over the fiberglass insulation on the outside. Moisture created inside the space would migrate out and be caught by the vapor barrier creating a bunch of damp, moldy, ineffective insulation. The barrier would go on the inside keeping the moisture out of the insulation. I would put a plastic barrier on the ground in the crawlspace however.

Half of my house is built over a crawlspace and the floor is insulated with kraft faced pink insulation with the kraft face up towards the living space.

If I were doing it from the start I would have either sprung for the spray in insulation or used sheets of rigid foam sealed in with cans of spray foam. It will be tight and moisture proof.

Over time the fiberglass will sag and be a nice home for rodents etc.


BTW.

Some of my water lines run through the crawlspace below the insulation. They are wrapped in the round pipe insulation and I only rarely have a problem and then only if I forget to run the water for a bit before going to bed.

[SolarGary]

Hi,
Another option that might be less work would be to handle it the same way that a lot of crawl spaces are now handled. You insulate the walls and the edge joists, and put poly film down on the dirt to keep the humidity level down. this is called a conditioned crawl space.

This is how I did mine:
http://www.builditsolar.com/Referenc...tion.htm#Crawl

And, more info here:
http://www.builditsolar.com/Projects...htm#Insulating
Search down a ways for the ones that mention "crawl space insulation".

The one just below this gives some info on insulating a floor from below.

The advantages of the conditioned crawl space approach are that it might take less insulation, and it is supposed to have less crawl space moisture problems.

Gary

[Old Vet]

The solid board is the one to use. Nail it up with large head nails.

[Wolf mom]

Nel:
there are large containers (like the ones used for gas BBQ's) you can buy on line for do it yourself uretahane foam.
I really like that idea and some day hope to be able to take the "pink stuff" out from under my home & foam it.

[The Paw]

Althought the "conditioned crawl space" and foam are both good options, I gather from your post those are not really what you are looking for.

I would suggest that you go ahead with pink insulation, but to hold it in place use the black cloth used under mobile homes. It is called belly wrap I think, and is very affordable. It is a tarry like cloth that rodents do not like to chew through, and it breathes.

Do not use poly, rigid insulation or even wood boards. All of these create a moisture barrier on the "cold side" of the floor, when moisture barriers should be on the "warm side" of the insulation. If you use these, air-borne moisture will travel through the insulation and then condense on the barrier, making your insulation wet.

[Nel frattempo]

Thank you everyone! Good ideas. I am not a big fan of closing up the crawl space...it just gives me the creeps.....so we keep vents open and insulate good. I think the plan now is to use pink stuff up under floor, top it with the black cloth stuff, and since we are using treated wood "skirt" then we will also pink stuff in between the studs of the skirt wall? Then black cloth to hold that in place and caulk it all up good. We have gravel down already under there and so I need to put plastic moisture barrier down too.....but I was not sure if I needed to put something down on the gravel first.....like the solid foam insulation pieces to keep the gravel from poking holes in the plastic?

[Sand Flat Bob]

Originally Posted by Nel frattempo

Thank you everyone! Good ideas. I am not a big fan of closing up the crawl space...it just gives me the creeps.....so we keep vents open and insulate good. I think the plan now is to use pink stuff up under floor, top it with the black cloth stuff, and since we are using treated wood "skirt" then we will also pink stuff in between the studs of the skirt wall? Then black cloth to hold that in place and caulk it all up good. We have gravel down already under there and so I need to put plastic moisture barrier down too.....but I was not sure if I needed to put something down on the gravel first.....like the solid foam insulation pieces to keep the gravel from poking holes in the plastic?

A little late for you to do it now, but I would have run the water and waste lines straight down through the crawl space and underground out to where ever they go. Then only pipes to insulate would be from ground level up to the equipment.
But that is just how I would have done it. Nothing wrong with lots of vapor barrier and insulation.

Bob

[morrowsmowers]

Can you run your pipes inside the house wall along the porch and make the connections there? That would eliminate some of the exposure and the house heat would keep those pipes from freezing.

Ken in Glassboro, NJ

[Beeman]

[QUOTE=Nel frattempo]The children and I built a porch and now want to enclose it to make a large mud room / laundry room. Since I want to move the washing machine and a sink out there, it will need to be insulated. We know how to do the walls, ceiling but I am wondering what I can do underneath. We store things ( kayaks / water tubs / luggage rack / tents ) up under there so I did not want to "under pin" it but may have to.......

Would it work to put the pink puffy insulation up under the floor, then seal up the under the floor with the solid insulation? That would put the water pipes up in the insulation........or is that not enough? Our drain line goes out to a gray water system and I don't think that would freeze up since the fall is so steep there would be no water holding in the line?

Or do I just need to go on and put some type under pinning around the whole bottom?





I would place heavy plastic on the dirt underneath and underpin the area with an access door. Heat and moisture both rise and damp insulation is useless. I would also place shotoff valves for the water lines in an area that you know doesn't freeze so if a real cold snap is predicted you can just shutoff and drain those lines and postpone wash day until it warms up. Also remember if you put any plastic type barrier attached to the floor joists that it will hold moisture against the joists. An area with plumbing always seems to have moisture even if it's the condensation from the pipes in humid weather. Also if you have a pipe leak/break it will hold all of the water against the insulation and floor.