Include concrete, excavation, temporary heat and moisture control specifications for cold weather.

How cold?

I wouldn't hesitate doing a poured or slab foundation with appropriate precautions and a heftier budget.

Masonry or stucco exterior walls can be done in winter with tenting and heat. But I would avoid wherever possible due to the extra costs and fire risks.

Breaking ground now would allow me to finish all framing and services in time for spring.

How cold?

Yes. I've seen posters here from the sweaty south complain of winter temperatures in the low 40s F.!

Im in NYC area which has been pretty cold over the past 2 weeks..teens. Normally we average in the mid 30's throughout winter.
What about a block foundation?

Money fixes everything in the building process. Just throw a couple of more bales of bills at it.

If you want to discuss the actual construction you need to tell us if there will be a full basement, soil conditions, cladding, etc.

I would use poured concrete for the foundation in the winter and avoid masonry work altogether if possible. If the weather is going to be this bad all season you will be forced pay a large premium for brick.

The contract with the builder is signed and the price is locked in. Here's what Im getting:

� Full 13 course extra height basement
� 3000 pound concrete for floorings
� Foundation coated w/ two coats of asphalt waterproofing
� 4" concrete basement floor over 4" crushed stone with interior and exterior perimeter drain pipe & sump pump as approved by the township
� Dura wall used between courses

I asked my builder about a poured foundation and he responded that it would drive up the cost and would require the plans to be resubmitted to the town.

We're building in Mass. Our foundation is in but they couldn't continue framing last Thursday and Friday because the temperature (around 15 degrees) was causing the equipment to seize. It was fine the previous days when the temperatures were in the mid to high twenties.

I would have thought concrete would be cheaper in cold weather; it will certainly be easier to protect from freezing. Block work will be extremely slow unless it is tented. Your contractor seems to be counting on a warmer February.

The plans should be submitted to the town regardless of the foundation type. If there will be no town review you had better hire an independent inspector.

The descriptions you listed are not adequate. 2 coats of waterproofing could be anything from a brush-on asphalt coating to cold spray-on rubberized asphalt. You definitely want the latter not the former whatever the cost. Unmodified asphalt cannot bridge cracks and is not an effective waterproofing.

4" crushed stone assumes very good soil conditions. Ask how the slab will be reinforced.

If you are going to have interior and exterior perimeter drain pipes & a sump pump then you have a very serious water problem. In areas like that a foundation of CMU with brush-on asphalt waterproofing is a very bad idea.

I recommend upgrading to concrete.

Renovator, Firstly..thanks for the guidance.

The building plans have already been reviewed and approved by the town. Going the poured route would require me to have the architect modify the plans and then wait for the town to approve the changes (prob another month).

Its a long story but the there was a house on this lot (1960's) with a block foundation that was destroyed in a fire. I had an inspector in the previous house and there were no apparent signs of water damage in the basement.

I dont think there is a serious water problem...the perimeter drains and sump pumps are standard for this builder...i guess its like wearing both a belt and suspenders.

I have a close friend who built a house with this builder in the same area and his basement stayed bone dry through both Sandy and Irene.

I would love to go the poured route but in the end estimate it would cost me an extra 8-10k plus a month delay. My builder thinks I can put that money to better use elsewhere.

Then ask him to use cold spray modified asphalt water proofing on the walls or better. A block wall is like a sponge.

I already did..I'm waiting for his response. Thanks for the heads up.

The contract with the builder is signed and the price is locked in.

A little late to be seeking outside opinions.

But perhaps you can add a plastic bubble membrane, such as Delta MS in addition to the next to useless quick asphalt spritz.

The membranes used to be Code in Ontario but were withdrawn at the lobbying of the subdivision builders. Nevertheless, the membranes are SOP for every infill house I've ever seen being built in Toronto.

I never use less than five inches of crushed stone under the basement floor.

The blockwork should be tented and heated, or, if laid up when it's above 40 degrees F., covered with insulating blankets for colder nighttime temps. Over the last week here, temps have ranged from -21 degrees C. to a predicted +12 degrees C.

This post was edited by worthy on Mon, Jan 28, 13 at 14:15

Money fixes everything in the building process. Just throw a couple of more bales of bills at it.

LOL hollysprings, I guess that is true with many things, huh.

I can only speak of my area. (MD.)

Here we do block with no problem. The masons mix antifreeze with there mortar and if it's extra cold they might drape some plastic over it.

Waterproofing here requires a coating and then a cover of polly. No problems so far.

The perimeter drains and sump pumps your builder is using are the important thing. That's where any falt in the overall system will show itself.

I go with trust your builder. Most really do want to do a good job.

Here are some precautions for winter CMU work:

- Most commercially-available masonry "antifreeze" admixtures are actually accelerators rather than freezing-point depressants. ASTM C1384 provides criteria for evaluating admixtures, including accelerators, for use in masonry mortars. Calcium chloride is commonly used in concrete as an accelerator, but its use in mortar is prohibited.

- Mortar shall be maintained above freezing until used.

- Sand or water shall be heated to produce mortar above 40 degrees Fahrenheit.

- Heat sources might be used on both sides of the masonry under construction.

- Wind breakers shall be installed if wind conditions are in excess of 15 miles per hour.

- Heated enclosures are recommended when the temperature drops below 20 degrees F.

- It may be necessary to heat sand to thaw frozen lumps when temperatures fall below freezing.

- To avoid flash set, heated water should be combined with cold sand in the mixer before adding cement.

- Do not lay masonry units having either a temperature below 20 degrees F or containing frozen moisture, visible ice, or snow on their surface.

- Masonry units should be kept dry, although very high absorption fired-clay brick may need to be wetted (but not saturated) prior to use.

Because of the heat released by the hydration process, poured-in-place concrete is far easier and faster to place in cold weather.

Cold weather affects masonry materials in various ways. First, cold temperatures slow reaction rates between cement and water, leading to delays in tooling and setting times, and reduce strength gain rates.

Also, cold masonry units can lower the temperature of mortar placed in contact with those units. If the units are cold enough, mortar temperature may drop below freezing. As water in the mortar freezes, disruptive expansion of the mortar occurs.

Wet or ice-covered unit surfaces prevent development of a good bond between the mortar and unit.

Cold weather also affects your laborers and may hinder the productivity and workmanship of masons. Unfortunately, extra activities consume more time as temperatures continue to drop.

The only reason to use CMU in cold weather is if the site is very far away from a concrete plant.

So is it fair to say that 40 degrees is the cutoff for when its safe to lay block?

Without special precautions followed to the letter. (I note that the Concrete Block Association in the UK advises not to set block below 3 degrees C. period, unless the temperature is rising.)

The trouble is that trades will often take shortcuts, especially if they think the builder/foreman isn't the sharpest chisel in the toolbelt.

I've seen masons running a blowtorch over mortar joints of bricks set in -20 C. temperature. Like that will do a lot!
*****
(Coincidentally, I just drove by a couple lucky infill builders pouring foundations today, as late January 6-12 degrees C. is a definite hot spell.)

This post was edited by worthy on Tue, Jan 29, 13 at 16:07

Then ask him to use cold spray modified asphalt waterproofing on the walls or better. A blockwork wall is like a sponge