We're getting really close to 'go' on our ICF project and I'm hoping you all can help me with a few of our outstanding questions:

Waterproofing - we're using the Platon system on the below grade walls.  Is this sufficient or should we also apply a spray-on/roll-on product as well?  If so, do you have any brand names that we could check into?

Exterior finish - What do you all use for the exposed foam between the bottom of your siding and your waterproofing?  Is there some sort of parging that is approved for application directly to the foam?  Speaking of siding, what type of screws do you use to attach vinyl siding to the ties? 

Designing HVAC - I'm having a hard time finding a local contractor that I feel comfortable with.  Most of them have worked with ICF in the past but their advice contradicts what I've read here.  Specifically, nobody is recommending that I use any sort of mechanical ventilation (HRV/ERV).  I'm also not real comfortable with their sizing estimates because they're using the 'years of experience' method and I want something a bit more scientific.  I'm going with conventional (gas) forced air heat.  The house is about 2450 square feet with a full walkout basement.  The proposals so far have been for between 3 and 4 tons, about 90k BTU and 16 or 21 SEER AC.  Do you feel it's worth spending the money for one of the Energywise style Internet design services or will that be insulting to my HVAC people?  Should I just keep looking until I find someone with a better sizing methodology? 

Thanks again for all your help

Matt

Posted By galnar on 06 Aug 2010 05:50 PM
We're getting really close to 'go' on our ICF project and I'm hoping you all can help me with a few of our outstanding questions:

Waterproofing - we're using the Platon system on the below grade walls.  Is this sufficient or should we also apply a spray-on/roll-on product as well?  If so, do you have any brand names that we could check into?

Exterior finish - What do you all use for the exposed foam between the bottom of your siding and your waterproofing?  Is there some sort of parging that is approved for application directly to the foam?  Speaking of siding, what type of screws do you use to attach vinyl siding to the ties? 

Designing HVAC - I'm having a hard time finding a local contractor that I feel comfortable with.  Most of them have worked with ICF in the past but their advice contradicts what I've read here.  Specifically, nobody is recommending that I use any sort of mechanical ventilation (HRV/ERV).  I'm also not real comfortable with their sizing estimates because they're using the 'years of experience' method and I want something a bit more scientific.  I'm going with conventional (gas) forced air heat.  The house is about 2450 square feet with a full walkout basement.  The proposals so far have been for between 3 and 4 tons, about 90k BTU and 16 or 21 SEER AC.  Do you feel it's worth spending the money for one of the Energywise style Internet design services or will that be insulting to my HVAC people?  Should I just keep looking until I find someone with a better sizing methodology? 

Thanks again for all your help

Matt

A lot of this has been thoroughly discussed over the past 2 -3 years. How much have you learned from searching these forums? It can be a chore, and can take you many hours to do it, but there's a wealth of info already posted that is exactly pertinent to your questions.

Waterproofing - Most here recommend both. I say it matters a lot how much water you can expect to come up against the house. If you're in a dry climate without much rainfall or sprinkler water to contend with then the Platon should be enough. That's all I used on my house.

Finish over foam - Search for my user ID and parging and you'll find what I did. Others have used other options. There is no generally used approach for this situation. Again, search on my ID and siding you'll find my strong advocacy that spiral nails are plenty good enough for siding attachment. You'll find several other opinions and experiences. Again, there is no one general approach.

There are several discussions on this ICF forum and the geothermal forums about HVAC. Off hand the numbers you quote look somewhat reasonable. Search for a discussion about spring time humidity to learn some thoughts about humidity removal and high SEER ac units. Where you live, amount of windows, thickness of insulation, house orientation, etc., has everything to do with sizing the heating/cooling system. Keep searching until you find a contractor who will use Wrightsoft HVAC software to calculate your loads. DO NOT short change this part of the house design. If you get it wrong you will never forgive yourself for your discomfort. Worse yet, your spouse won't forgive you either. When it comes to HVAC honesty and competence do not come cheaply. In some parts of the country you can get by without an ERV or HRV, but you cannot get by without forced ventilation, i.e., in some cases it may be cheaper to just have fresh air ventilation and not worry about the cost of lost heat or cooling.

I've tried using the search tool. Unfortunately, it sucks. The search by user doesn't work at all. Regardless, thanks for your input.

Posted By galnar on 06 Aug 2010 07:43 PM
I've tried using the search tool. Unfortunately, it sucks. The search by user doesn't work at all. Regardless, thanks for your input.

What sort of issues are you having with the search tool. Here's a PDF of a search I just did. Looks like it brings up just about everything I've posted on parging.

Note my selections for the search.

Oops, just looked at the PDF and see that the selection drop downs did not print. I selected Subject & topic, ANY keyword, All posts by age, dmaceld for user, and all forums.

I've had problems trying to search as well and have had problems, so I can understand that. There was however a post regarding "waterproofing ICF basement" four post below, so that really didn't need to be searched...I digress. Also, if you are looking to build or new to this forum and asking questions, if you tell us where you are building that could REALLY help. Its possible either one of us could help you or we know someone that can help you.

I will post my response regarding waterproofing listed 4 posts below

Hello Slatel,

One of my best friends has a place in Mcleod which is about an hour awayfrom you. Anyway, to answer your question you normally want to use a peal and stick waterproofing system, like a bituthene waterproofing system. You can also use a protect the waterproofing membrane with a system platon...google it. There are other types of waterproofing systems out there, but just be sure that the one you chose is not petroleum based, as it will eat away the EPS.

You may want to search the forum as well, as it has been discussed often.

Best of luck,

renangle

Thanks renangle, I read that post, and have read many positive sentiments about the merits of the peel and stick products such as the Platon. I was wondering specifically about the use of a spray/roll on product in conjunction with a peel and stick. Is it overkill to use both? I haven't seen that discussed anywhere here or on JLC or Gardenweb. I'm building in Central IL near Peoria. I've followed with great interest Clark's thread on controlling springtime humidity and have absorbed as much other relevant HVAC info as I can get my hands on! I think I know what needs to be done with regard to that but I was hoping for some first hand experience using a design service and then tactfully asking your HVAC installer to follow it.

For ~$60 you can order the software and do your own (or check other's results) sizing for your ICF home HVAC system here:

HVAC Sizing for Concrete Homes

Note that many peel-and-stick waterproofing manufacturers recommend a primer be applied to the EPS foam prior to applying the peel-and-stick membrane.  This insures better adhesion of the membrane.  Also,  some manufacturers, TAMKO in particular, offer a mastic compound that is applied at all joints and edges to further insure a waterproof seal.

TAMKO TW-60 is what my local ICF distributer sells and installs on below grade walls.

Sheet Waterproofing Manufacturers

That software looks promising. I just ordered it, came out to about $90 by the time they add tax and shipping! Thanks for the links.

Posted By arkie6 on 07 Aug 2010 12:18 PM
For ~$60 you can order the software and do your own (or check other's results) sizing for your ICF home HVAC system here:

HVAC Sizing for Concrete Homes

I used that one, as well as HVAC Calc from Don Sleeth and HEED from UCLA. HEED is free. HVAC Calc is $50 for a 2 month license. HVAC Sizing gave me a heat load of ~22k Btuh vs about 33k Btuh from Wrightsoft. Wrightsoft, HVAC Calc, and HEED all use Manual J calc methodology. HVAC Sizing runs on Excel. I don't remember that the PCA website made that clear. I installed a 3 ton heat pump which has proven to work very well in heating/cooling my ICF house. It's a good thing I didn't go with a 2 ton unit which HVAC Sizing indicated would be enough. HVAC Sizing is a good program, and good for giving you something to compare to, but it is far from being an end all, be all, program.

The single greatest difference between Wrightsoft, which HVAC contractors use, and the other programs is that Wrightsoft will give you a very good room by room heating/cooling load calc. That can be critical in doing duct sizing, which Wrightsoft also does and the others do not. If you have a room with a lot of south window exposure and a north side room with minimum windows you can have a substantial heating/cooling load difference between them. If you don't account for that you can end up with some uncomfortable temp differences and/or air drafts in the house.

You are going to have a little bit of challenge using a gas furnace for heat. If your heat load number is around 40 to 50k Btuh you may have trouble finding a gas furnace small enough to give you comfortable heat. Ideally, the furnace size should be such that on the coldest design day it will run 100% of the time. This means that on days when the heat load is only 20% of maximum the furnace will only run about 20% of the time. If the furnace is oversized you can end up with hot and cold cycles in the house. Fortunately, with ICF the indoor temp will not fluctuate nearly as quickly as in a stick built house. A good competent HVAC contractor can help you select a furnace and air conditioner that will inject, or remove, heat into/from the house at a rate that matches the heat loss/gain of the house.

galnar, my concern with the idea of tactfully getting an HVAC contractor to follow the calculations of a design service is that having to do that indicates the contractor does not really understand the energy dynamics of a house. And if he doesn't understand issues of indoor air quality, required air flow rates to properly heat & cool a house, duct sizing, blower sizing, fresh air ventilation, etc., I wouldn't want him to do my system. My HVAC contractor nephew, who understands all this stuff and uses Wrightsoft, has related to me many horror stories of heating/cooling systems that didn't work properly, caused a lot of discomfort, and in the end cost owners a lot more money than they should have, and that he went in and corrected. That is why a local city, Nampa, ID, now requires all home HVAC installation building permit requests must be accompanied by Manual J & Manual D calculations.