foundation venting

[lefties]

Why do I see so much conflicting info about how much venting is needed in foundation? I am adding vents to foundation today(wow what a job knocking out blocks-WOW) All my floors have gone wavy,,contractor had only put 6 sliding aluminum vents in when done. Around here I never see more than that added,,and according to the chart I read it said I should have 21 under my home at 1500 sq ft. Of the self opening closing variety.

[altasnowman]

Hi lefties,
I use as a rule one square foot of open venting for every150 square foot of floor. If you use a vent that has a insect screen or louvers then add another 35% to your venting area. in your cases you should have approx 13 to 14 square feet of venting. you should have your vents on all sides,so if you go with 14 sq. ft. you should have 4 3.5 sq.ft. vents for your home. Mark has this information in his repair manual in chapter 24. You can purchase this book from the Book and parts link at top of page.

[Greg]

The "book" call for 1 sq. foot of vent for every 150 sq. foot of floor. there are also thermostatic self closing & opening vents. I really don't think you can have too much ventilation especally in warm weather. Greg

[lefties]

I have the book,,but i want to know why you NEVER see that many vents under any houses here period. Is it just so much because we have particle wood floors?

[altasnowman]

Hi, In the old days (dating myself LOL) when I was hauling homes to dealers and to sites the dealers would try to get job of blocking and skirting done as cheap as possible and vents were something that they could cut corners on.Also when most people would ask about venting they would have the add-age that this is an area that does not need air circulation because of cold weather, and it was a way for critters to get in to the home.Today we know better but there is still a lot of old thinking out there yet.

[lefties]

sorry i called u jim

[altasnowman]

No problem Have been called worse LOL

[lefties]

[Maureen]

Hey lefties, good to see you again!

Now, you haven't placed your profile on line, so I'm working on my old memory here. Didn't you recently buy a new place? Correct me if I'm wrong!

Anyway, here's my theory on venting. If you're in a park, you can pretty much go with the recommended square foot rule. If you have your own property, then other things might come into play. You might be sitting on top of an underground spring that causes more moisture in the ground!

Now, this is an area that I have no experience in at all. We do dry and drier in my area LOL! But you might want to install a vapor barrier and more vents? If your floors are becoming wavy, you've got a whole lot of moisture coming from somewhere! I'd check for plumbing leaks first! On the other hand, if you life in the midwest, or Texas, you've already had your fair share of rain this year!

Give us some more information about your home... or refresh old memories lol! We'll do our best to help you out.

Maureen

[lefties]

Hi Maureen,, Thx-I did place profile once b4 remember? Do I have to do it again? Thx-ok,,ill re-do it again,,but your memory serves wel!!!!

[Guest]

When I bought this '72 Newport 70' single-wide, it had the original metal skirting and NO vents whatsoever. The skirting had deteriorated to the point where the only air circulation was from the many holes in it that were never repaired. I replaced it with new vinyl skirting bought at a local MH parts store. When I asked the owner why there were no vented panels in the skirting kit, he said "the skirting panels sit so loosely in the top and bottom rails that you get plenty of air circulation." HUH - WHAT? I knew that had to be wrong. So I bought 18 vented panels and evenly spaced them around the perimeter. I have a full cement slab, so I don't get much ground moisture coming up, but I'm still thinking I need more venting. This is a MH problem that everyone seems to have a misguided opinion about and NONE of my neighbors have any noticeable venting installed either. I suspect venting in these northern climes is frowned upon as a waste of energy and an invitation to frozen water lines. Whatever the reason, I think I'll dig out my copy of Mark's book and go over that chapter on venting again and maybe add a few more. Mark's book has already saved me a lot of time, money and aggravation and at least I'll KNOW I've done it right.

[lefties]

I added another 6 vents for total of 12 so far,i have a big fan underneath,,crawled under house today to seal vent and there was water dripping off the belly in a cpl spots. Im sure there arent any water leaks. We had a flood this past week around here and my pit foundation had a little water under it. The sump ran for a cpl days. Is the droplets and dripping off the belly indicative of anything else? Or is it just the outside air getting in and hitting the colder crawlspace air and condensing on the cooler belly material?

[Greg]

Is the water coming through the belly or condensing on it? If it coming through it I would take a closer look just to be sure it is not a leak. Greg

[lefties]

looks to me like its condensing on it.

[Greg]

If that is what is happening then opening up the skirting & getting some air moving should help. I may be tempted to take a couple of sections down for a few days to let it dry out. Greg