Building a new house

[tegguy]

My wife and I recently signed paperwork to build a new house with a production builder. We were picking out cabinets and stuff today we were asked if we wanted to fill the concrete block exterior walls with foam. I hadn't heard of this before and was curious what everyone's thoughts are on it if it's worth it or not. They said it would cost about $850 to fill the walls. The house we are building is 3854 sq ft 2 story in Florida. I know it's a massive house more than we were looking for but it was a good price in a good location.

Thanks

 

[zporta]

I haven't heard of this before. Is most of the block in ground? If so I probably wouldn't worry about it. The ground is a great insulator not sure some insulation would help much with changing temps

 

[jack stand]

Spray foam or loose? If it is spray foam that sounds like a cheap price. Are all the exterior walls (the shell) block? I can not speak with any authority of FL construction (or climate), but I think that any "upgraded" insulation pkg. needs to continue up to & include your roof. You got to be getting tremendous heat gain from a roof in FL. I am assuming that they are above ground block walls you are describing.
Enjoy your new home!

 

[tegguy]

I believe its spray foam inside the hollow area of the block. The exterior walls of the whole first floor are block construction

 

[zporta]

Well if its the first floor I would do it for sure, seems cheap. Just make sure they do it and try and just make a little extra $ off you

 

[LB-1911]

I believe its spray foam inside the hollow area of the block. The exterior walls of the whole first floor are block construction

I'd do it.

Block Fill
Block Fill Insulation is a “dry” resin foam-in-place insulation product designed for the cores of concrete block walls. It is competitively priced and is equal to or superior to all current foam-in-place products specified. Block Fill Foam is a Class 1/Class A fire rated product and meets or exceeds all testing requirements of current standard building codes.

Block Fill Foam is injected under pressure into the empty cores of exterior masonry block walls. As foam fills the block cavities, pressure forces the insulation into adjacent block columns and seals even the smallest cracks and fissures. The insulated block forms a protective envelope around the building, preventing air leaks, sound transmission, mold, mildew and bacteria growth, and sealing out moisture, pollutants and allergens.

Block Fill Foam Insulation is typically used in commercial and institutional building new construction such as retail box stores, schools, and churches. It is also used in residential new construction applications such as concrete-block stucco walls, foundations, and basement walls.

Source of above

http://energysmartinc.com/insulation/spray-foam/block-fill/

 

[where2]

Do it. My neighbors did it and spray foamed the attic when they rebuilt their house a few years ago. Their house is now like an igloo ice chest. When we get a cold snap, it's days before they turn on the heat. They love it.

 

[jack stand]

I believe its spray foam inside the hollow area of the block. The exterior walls of the whole first floor are block construction

Still, don't let your insulation "package" above your foam areas (wood framing) fall below the rated insulation value of the block w/foam, or it's wasted money. The a/c cooling costs (reverse of my situation) must be pretty high in the summer and either way, heating or cooling, insulation is going to save you $$ every month for the life of the bldg. Again, I don't know about FL., but the $850 put towards the roof area might be better spent?? Check out http://www.greenbuildingtalk.com/Forums.aspx
It's a "greenie" site but in many ways, green is also cheap, a condition that fit's me well and there are a bunch of smart folks there that can help much better than a guy in Maine trying to help a guy in FloridaKeep up your reasearch.

 

[tegguy]

I'll check out that site. This is the only insulation upgrade we are offered. The roof is a 30 year warranty roof

 

[72Anthony]

I second the recommendations to look at your entire insulation envelope. If you are going to have a conventional ventilated attic, you want to have a radiant barrier on your roof. Techshield is a trade name, that is OSB roof sheathing with a layer of aluminum foil attached that faces the inside of the attic. This greatly reduces the heat transfer into the attic, and thus the house.

An even better, though more expensive option is to spray foam the roof, no ventilation, no openings. This keeps the ductwork in the attic from heating up.

A lot of this research originated in Florida.

 

[Jdbuilder]

Do it, block has a horrible r value. With foam injected in it it can achieve an r value of 11.

Also highly recommend radiant barrier with a ridge vent and vented soffits.

 

[CNGsaves]

Agree to do all the insulation you can afford . . . . go for it.

While you're in planning stages, also wire ENTIRE house for technology that might be needed . . . ie Coax RG6 and Cat 5e/6 to where-ever you might want TV or internet. Also, good idea to install conduit from upper floors (including attic) down to unfinished room that can serve as your central distribution room for those home-runs of cabling (ie for TV splitter or ethernet switch). The attic conduit is essential so that any satellite service you might have easily can be connected to internal house cabling . . . WITHOUT . . . a single outdoor cable routed around exterior of house that looks like ****.

 

[Conductor562]

What's an $850 option on a nearly half million dollar house?
Why the hell not.
The more insulation you can afford, the better off you are.

 

[tegguy]

I second the recommendations to look at your entire insulation envelope. If you are going to have a conventional ventilated attic, you want to have a radiant barrier on your roof. Techshield is a trade name, that is OSB roof sheathing with a layer of aluminum foil attached that faces the inside of the attic. This greatly reduces the heat transfer into the attic, and thus the house.

An even better, though more expensive option is to spray foam the roof, no ventilation, no openings. This keeps the ductwork in the attic from heating up.

A lot of this research originated in Florida.

Unfortunately since this is a production builder not a custom builder we only have so many things we can change. For insulation and roof we only have the option on the foam filled block.

Agree to do all the insulation you can afford . . . . go for it.

While you're in planning stages, also wire ENTIRE house for technology that might be needed . . . ie Coax RG6 and Cat 5e/6 to where-ever you might want TV or internet. Also, good idea to install conduit from upper floors (including attic) down to unfinished room that can serve as your central distribution room for those home-runs of cabling (ie for TV splitter or ethernet switch). The attic conduit is essential so that any satellite service you might have easily can be connected to internal house cabling . . . WITHOUT . . . a single outdoor cable routed around exterior of house that looks like ****.

Doing this to an extent they are charging ridiculous prices to do stuff. $350 for a 220 outlet in the garage. $60 bucks per coax drop, $45 per cat 5e drop (this isn't too bad but it's rough in only I'll terminate). All our rooms are finished but I have a 2 post equipment rack I'm planning on installing in the laundry room to hold the networking stuff, coax distribution, and whole home audio equipment if we do it. I'm not doing much on the second floor since I can do everything myself after the fact I'm just planning ahead on the first floor. We have a limited budget so we are trying to do what we can and leave out the stuff that we can do later.

 

[paulrey27]

I'm saying no way. I think most of the people here seem to be forgetting that insulation envelope involves thermal breaks...in which a concrete block has 3 nice thermal connections... sure you'll see some value but I'd rather have the insulation on the outside of the block.

 

[tegguy]

I'm saying no way. I think most of the people here seem to be forgetting that insulation envelope involves thermal breaks...in which a concrete block has 3 nice thermal connections... sure you'll see some value but I'd rather have the insulation on the outside of the block.

Insulation on the outside is no option unless we want to take off the stucco after moving in and then re-stucco (way too much cost). I am leaning towards doing it because it will be a good sound deadener and added R value or only 850 it might be worth a shot.

 

[paulrey27]

Insulation on the outside is no option unless we want to take off the stucco after moving in and then re-stucco (way too much cost). I am leaning towards doing it because it will be a good sound deadener and added R value or only 850 it might be worth a shot.

Sound traveling through a solid medium...will still use the webbing from the block. Don't mean to sound like a Debby Downer but I really can't be sold on thermal/acoustic qualities of filling the cavities. Especially not for 850$.

Sounds like I need to become a builder/developer.

 

[tegguy]

Sound traveling through a solid medium...will still use the webbing from the block. Don't mean to sound like a Debby Downer but I really can't be sold on thermal/acoustic qualities of filling the cavities. Especially not for 850$.

Sounds like I need to become a builder/developer.

While it will still use the webbing I would think that it would be an improvement over nothing being there and traveling through the open cavities.

 

[paulrey27]

While it will still use the webbing I would think that it would be an improvement over nothing being there and traveling through the open cavities.

That's the point.
The open cavities.

 

[sickjuice]

Doing this to an extent they are charging ridiculous prices to do stuff. $350 for a 220 outlet in the garage. $60 bucks per coax drop, $45 per cat 5e drop (this isn't too bad but it's rough in only I'll terminate). All our rooms are finished but I have a 2 post equipment rack I'm planning on installing in the laundry room to hold the networking stuff, coax distribution, and whole home audio equipment if we do it. I'm not doing much on the second floor since I can do everything myself after the fact I'm just planning ahead on the first floor. We have a limited budget so we are trying to do what we can and leave out the stuff that we can do later.

Thats dirt cheap for my area. We charge well over $100 per data opening. Heck even the companies that just do data and don't have to pay their guys near as much charge over $100

 

[tegguy]

Thats dirt cheap for my area. We charge well over $100 per data opening. Heck even the companies that just do data and don't have to pay their guys near as much charge over $100

This is for only running the wires no termination or anything. Also it's 5e not cat 6 like I'd prefer.

 

[CTyankee]

I'm saying no way. I think most of the people here seem to be forgetting that insulation envelope involves thermal breaks...in which a concrete block has 3 nice thermal connections... sure you'll see some value but I'd rather have the insulation on the outside of the block.

Another no vote here...besides the problem of verifying that all voids in the block are indeed actually filled...as mentioned there is still a lot of thermal bridging that is going to take place. We've poured double walls with a foam interior, which is effective because it eliminates all thermal bridging.

Unless the builder can provide some proof of real-life energy savings..I'd pass and put the 850 towards some other energy saving means.

 

[tegguy]

Unless the builder can provide some proof of real-life energy savings..I'd pass and put the 850 towards some other energy saving means.

Like what? The fact there there is less thermal bridging is a difference. The fact is the open air cavities provide a much greater surface area for thermal transfer than the webs.

 

[cowboyjosh]

Go for the insulation, you know your climate better then some of the internet experts that have replied. Do all the upgrades you can afford, more wiring, more insulation; get the best infrastructure you can afford at the time of construction; you can always add granite and other cosmetic bull ****; but after the walls are up its tough to add more insulation and wiring.

One thing the production guys might not budge on, but I would ask, is I would not bury any PEX, or copper water pipes in the slab.

Oh, and in Florida even though you have a concrete block house, still opt for the termite pre-treat if thats an option; those bastards will still find wood, my family has a place in Marco Island and termites are a huge pain in the ***.

 

[tegguy]

Go for the insulation, you know your climate better then some of the internet experts that have replied. Do all the upgrades you can afford, more wiring, more insulation; get the best infrastructure you can afford at the time of construction; you can always add granite and other cosmetic bull ****; but after the walls are up its tough to add more insulation and wiring.

One thing the production guys might not budge on, but I would ask, is I would not bury any PEX, or copper water pipes in the slab.

Oh, and in Florida even though you have a concrete block house, still opt for the termite pre-treat if thats an option; those bastards will still find wood, my family has a place in Marco Island and termites are a huge pain in the ***.

Basically we are doing as much electrical on the first floor we can afford and I'll do the second floor later. We have an island so we will have to have plumbing electrical and drain in the concrete. I plan to do all the second floor low voltage myself later. Granite comes standard in the house and we kept our upgrades to stuff that was cheaper or we didn't want to do later (for example we only got the included tile and carpet elsewhere I'll put in tile or hardware in the other areas myself later)

 

[CNGsaves]

Doing this to an extent they are charging ridiculous prices to do stuff. $350 for a 220 outlet in the garage. $60 bucks per coax drop, $45 per cat 5e drop (this isn't too bad but it's rough in only I'll terminate). All our rooms are finished but I have a 2 post equipment rack I'm planning on installing in the laundry room to hold the networking stuff, coax distribution, and whole home audio equipment if we do it. I'm not doing much on the second floor since I can do everything myself after the fact I'm just planning ahead on the first floor. We have a limited budget so we are trying to do what we can and leave out the stuff that we can do later.

Thats dirt cheap for my area. We charge well over $100 per data opening. Heck even the companies that just do data and don't have to pay their guys near as much charge over $100

Not "too bad" on the rough-in price for data runs, except it's still highway robbery when you have 20 or more drops !! I had unfinished basement and I probably added 10 just in Coax in the basement (not counting data/telco) as I had 3 Coax in the living room alone, and always had 2 Coax in each bedroom on different walls (ie for options in room layout). I also drilled more runs in studs underneath for walls upstairs and fish-taped coax/telco/data into a combo box. I'm guessing an "expert" would have charged me $1500 to $2000 or more for work I did.

If builders are charging $60 Coax + $45 Data for run in the same box, that's crazy when still so easy with bare framing.

I'd recommend anyone building new house have CLAUSE in the contract that owner can put in his own Coax/Ethernet/Telco/stereo/speaker runs that he chooses while the framing is still wide open!!

 

[tegguy]

I asked if I could do my own low voltage they wouldn't let me. I did it in my parents house and ran 2 coax and 2 cat 5e to at least 2 locations in each room. It ***** they wouldn't let me cause I would have done a lot more. I'm doing all the second floor low voltage myself except for the stuff thats included. Everything will run back to the laundry room to a 2 post rack I have. I wish I could have 2 tv and at least 2 network in each room

 

[CTyankee]

Like what? The fact there there is less thermal bridging is a difference. The fact is the open air cavities provide a much greater surface area for thermal transfer than the webs.

High energy efficient appliances, window treatments, etc. Air is a pretty crappy heat conductor compared to block.

Might want to do a little more research yourself. Besides companies offering the process, I haven't read much of anything that suggests any benefit to doing so. That said...it's your house. If you think it will make a difference, go for it.

 

[tegguy]

High energy efficient appliances, window treatments, etc. Air is a pretty crappy heat conductor compared to block.

Might want to do a little more research yourself. Besides companies offering the process, I haven't read much of anything that suggests any benefit to doing so. That said...it's your house. If you think it will make a difference, go for it.

All the appliances are included with the house and all except the fridge are GE profile line appliances.

I am trying to do some research I didn't find much on google (partly becuase I didn't know what to search for) and so this is why I'm turing to forums and people who might have some experience.

Concrete based on density has a K value of .2-1.4 Air has a K value of .024 the higher the K values the better it is at transferring heat. Although concrete transfers heat better it's not astronomical and I'd venture to guess the heat transfer even's out in this application due to the volume of concrete webs vs the volume of air.

 

[BD1]

I would spend the $850.00, sounds cheap not to mention difficult to do later.
Is the electric 220 outlet romex ? If not, I would have them run a 1'' conduit to garage and install a separate panel and outlets later. Just allow breaker space for sub panel.

 

[tegguy]

I would spend the $850.00, sounds cheap not to mention difficult to do later.
Is the electric 220 outlet romex ? If not, I would have them run a 1'' conduit to garage and install a separate panel and outlets later. Just allow breaker space for sub panel.

The 220 outlet is for romex, outlet, and breaker. The panels are in the garage but the location I want the 220 wouldn't be possible unless I ran it externally.

 

[paulrey27]

All the appliances are included with the house and all except the fridge are GE profile line appliances.

I am trying to do some research I didn't find much on google (partly becuase I didn't know what to search for) and so this is why I'm turing to forums and people who might have some experience.

Concrete based on density has a K value of .2-1.4 Air has a K value of .024 the higher the K values the better it is at transferring heat. Although concrete transfers heat better it's not astronomical and I'd venture to guess the heat transfer even's out in this application due to the volume of concrete webs vs the volume of air.

Sounds to me like 850$ is worth it to you to just say you have insulation in the wall...in which case you should just go ahead and do it, right?
8 times isn't astronomical but it's huge. Point is there are typically 3 thermal bridges in a 16" long block (making assumptions here)...insulating the cells of a block to keep the thermal transfer down is like a castle that is under siege and can't close it's three draw bridges so it digs an extra wide moat. Odd example I know but anyone trying to get in through the moat is only slowed down...the bridges are still open and fair game.

As myself and only one other person has said, we don't think it's worth it. Also like he said, it's your house, your money, so it's your decision. In the grand scheme of things...850$ isn't a lot to what you're paying for the entire mansion, which I assume is well over 300,000. At that price, 850 is only almost a third of a 1%.

 

[tegguy]

It isn't worth it just to say I have it there has to be a return on investment otherwise it would have been done already. The house is costing low to mid 300k

 

[Ray Kelly]

Absolutely!! Do it!! I have seen them do it on This Old House And Bob Vila. It fills the holes in the concrete block and helps insulate the house tremendously..

 

[tegguy]

Core foam is the name of the product

 

[paulrey27]

so the block R-value goes from 1.1 to 7.2...roughly.
What are the code requ's for insulation down there?
You can get that kind of R-value from 1" of rigid insulation on the exterior face and then you'd also cut out the thermal bridging. After digging deeper, I'd say some is better than none. and 850$, I can't speak to the cost but I'm just not happy with how the builder sold this. What's the name of the builder, if you don't mind me asking.
Also if I can ask, why not a wireless router? I'm big on wired stuff but the shift in tech towards wireless might make sense to save some money where you can on those items?

 

[nolimits76]

Do you guys use HERS rating in your area? It's basically an efficiency index that shows how efficient (or inefficient) your house is. The lower the number, the better. I custom built a house 5+ years ago and this didn't exist. We just recently signed a contract on a different house a few weeks ago and I became acquainted with it.

The neat thing is the HERS rating takes into account the wall insulation, roof insulation, windows, doors, etc. so you get an overall idea how efficient your home will be.

Just a thought to consider.

http://www.resnet.us/hers-index

In regards to cable drops & conduits, plan for the future. Don't bust your budget, but figure you will expand later on and with concrete block walls, having conduits will be a life saver.

 

[matthew_turner]

I'm saying no way. I think most of the people here seem to be forgetting that insulation envelope involves thermal breaks...in which a concrete block has 3 nice thermal connections... sure you'll see some value but I'd rather have the insulation on the outside of the block.

I agree, cannot forget about thermal breaks…

What about rigid on the interior (build out the wall) if exterior isn’t an option?

 

[paulrey27]

i agree, cannot forget about thermal breaks…

what about rigid on the interior (build out the wall) if exterior isn’t an option?

this.

 

[tegguy]

so the block R-value goes from 1.1 to 7.2...roughly.
What are the code requ's for insulation down there?
You can get that kind of R-value from 1" of rigid insulation on the exterior face and then you'd also cut out the thermal bridging. After digging deeper, I'd say some is better than none. and 850$, I can't speak to the cost but I'm just not happy with how the builder sold this. What's the name of the builder, if you don't mind me asking.
Also if I can ask, why not a wireless router? I'm big on wired stuff but the shift in tech towards wireless might make sense to save some money where you can on those items?

The builder is D.R. Horton. Wireless routers are good for convience but they do not have the throughput that is needed for stuff like HD streaming and as the distance increases the signal decreases. Plus wireless is finiky (sp).

Do you guys use HERS rating in your area? It's basically an efficiency index that shows how efficient (or inefficient) your house is. The lower the number, the better. I custom built a house 5+ years ago and this didn't exist. We just recently signed a contract on a different house a few weeks ago and I became acquainted with it.

The neat thing is the HERS rating takes into account the wall insulation, roof insulation, windows, doors, etc. so you get an overall idea how efficient your home will be.

Just a thought to consider.

http://www.resnet.us/hers-index


In regards to cable drops & conduits, plan for the future. Don't bust your budget, but figure you will expand later on and with concrete block walls, having conduits will be a life saver.

We have the HERS rating on the house but I don't know what it is off the top of my head it's at home. I do know it was pretty good as the house was planned.

I agree, cannot forget about thermal breaks…

What about rigid on the interior (build out the wall) if exterior isn’t an option?

Once again we would have to tear down the drywall after the house is finished and put it in then redo everything (massive cost). I'm not trying to be stubborn but the problem with production builders is they have very limited changes you can make. Adding a 220 outlet was almost like pulling teeth and I paid out the A** for it.