01. What is autoclaved aerated concrete?
02. How is wiring installed in SafeCrete AAC walls?
03. How can I find installers in my area?
04. How much does SafeCrete AAC cost?
05. Is SafeCrete AAC load-bearing?
06. Can SafeCrete AAC be used in the construction of
stem walls?
07 . Can this product be used for basement walls?
08. Do AAC walls require insulation?
09. What is the R-Value of a SafeCrete AAC wall?
10 . How durable is AAC in various climates?
11 . Is a vapor barrier required in exterior applications?
12 . What type of mortar is used with SafeCrete?
13 . What type of finishes are available?
14. Is SafeCrete AAC like EIFS?
15. Can gypsum board or sheetrock be used on SafeCrete
AAC walls?
16. What type of roofing material can be used over SafeCrete
roof panels?
17. What type of surface treatment is required for SafeCrete
floor panels?
18. What are the guidelines for AAC installation in
severe heat or cold?
19. Is fly ash used in SafeCrete AAC production?
20 . Why is SafeCrete considered a "green"
building product?
21 . What tools and accessories are needed to complete
my order?
22 . What is the lead-time for my SafeCrete order?
23. Where are SafeCrete products manufactured?
24. Are vertical cores required?
25. Does SafeCrete construction qualify for LEED certification?
26. What is the difference between Safecrete AAC and
non-autoclaved aerated concrete?
27. What is the SafeCrete return policy?
Autoclaved aerated concrete (AAC) is a lightweight, precast building
product used around the world. Available in blocks and panels of various
sizes, AAC is an ideal material for structural walls, firewalls, soundwalls,
floor and roof systems. See our Introduction
and Benefits slideshow.
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Easily. People often imagine that wiring will be a challenge due to
the solid structure of AAC blocks. When they discover how versatile
and workable AAC really is, they are pleasantly surprised. There are
3 standard methods for installing wiring in autoclaved aerated concrete
walls. Many installers use a combination.
Routing: Build the walls first. The electrician
draws directly on the block to indicate where the wires will go.
The AAC installer uses a manual or electric router to cut channels
on the inside of the walls. After the electrician installs the wiring,
the wall is plastered or sheetrocked. Requires no pre-planning,
and changes are easily made. Conduit usually required.
Behind Sheetrock: If sheetrock is being attached
to the AAC wall with furring strips, then installing the wiring
between the sheetrock and the block is a no-brainer. This method
does not require conduit; however, wires and cables must be protected
when crossing the furring.
Inside the Wall: With this method, the majority of the
conduit is installed as the wall is built. For example, the installer
may use a course of U-block at the height where the electrical receptacles
will be, filling in the cavity with concrete after the conduit is
installed. Wiring may also be run in the vertical cores. Pre-wired
conduit is typically used to reduce the hassle of pulling wires.
Wiring is deep in the wall and surrounded by a fire retardant material.
Extra switches and receptacles can still be added by the routing
method.
See
Slide Show
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SafeCrete AAC may be installed by masons, carpenters or specialists.
We provide free training for installers
using SafeCrete materials at the SafeCrete marketing center. If there
is an authorized SafeCrete dealer in your region, they will be happy
to provide you with the installation information or even an installed
bid. Safecrete Dealers are listed on the Contact
Us page.
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SafeCrete pricing is very competitive with other quality building
materials. Unit costs may be found on our Products
Page. Installed cost and operating cost must be considered as
well. These costs are all affected by project size, location, labor
market, current freight rates, building codes, and the particular
application. Autoclaved aerated concrete typically pays for itself
within 3-5 years. For your convenience, we have provided some sample
job costs on our Pricing Page.
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SafeCrete AAC blocks and panels with a minimum of 8" thickness
are suitable for load-bearing applications, when used in accordance
with our published design aids and allowable stress listings. 6''
blocks may be used for some interior loadbearing applications. Loadbearing
applications require vertical cores reinforced with rebar and concrete.
Code requires cores at corners, doors and windows. For design information,
please consult our Technical
Manual, or contact
us to request a technical manual on CD.
For non-loadbearing applications, we supply 4" blocks, 6"
blocks, and aerated cladding panels as thin as 2".
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Yes, AAC may be used for stem walls. Stem walls should be protected
against permanent exposure to water by applying waterproofing material
such as bitumen coating on any surface in contact with soil. For exposed
surfaces (above grade) that will be finished, use a cementitious waterproofing
to improve adhesion of the finish.
Autoclaved aerated concrete walls may be constructed on top of AAC
stem walls, concrete slab, or concrete masonry units.
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Yes. The walls must be designed correctly to account for axial loads
when used as a basement retaining wall. Due to the extreme horizontal
pressures exerted by backfilling, thicker walls with additional vertical
conrete and rebar reinforcement should be used, as specified by a
qualified structural engineer. All walls below grade should be waterproofed
as discussed above.
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Almost never. SafeCrete AAC walls are insulated by millions of tiny
air cells which reduce thermal conductivity. The thick walls also
benefit from high thermal mass, much like a log home. AAC block walls
at least 8" thick typically provide sufficient insulation in
southern climates. For more information, please see our Energy
Efficient page.
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The thermal performance of AAC is equivalent to R-20 insulation. AAC
combines the advantages of low thermal conductivity and low air-infiltration
with high thermal mass. This product is used in every climatic region
of the world, from humid South America, to the dry heat of the Middle
East and the severe cold of Finland. Insulation is rarely added; the
walls are simply thicker. For more information on thermal performance
testing, please see our Energy Efficient
page.
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Autoclaved aerated concrete is extremely durable. It does not rot
or decay like wood or other organic materials. It does not rust like
metal. Termites and other pests do not eat it. AAC will not burn.
The millions of tiny cells in AAC cushion buildings from major force,
preventing progressive collapse. AAC has withstood earthquakes in
Japan, the frigid temperatures of northern Europe, the harsh salt
air of the French Riveria, and the hillside fires of San Fransisco.
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No. AAC construction provides a solid, monolithic wall system with
an enclosed, non-connected cellular structure. Exterior finishes are
designed to complement this structure, providing a healthy balance
between moisture resistance and vapor diffusion. The positive pressure
of the air conditioning system pushes water vapor out through the
walls, while preventing moisture penetration from the outside.
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Thin-bed mortar designed especially for AAC is used to install SafeCrete
blocks and lintels. It is sold in ready-to-mix powder form. Thin-Bed
Mortar is polymer modified Portland cement specifically designed to
bond our blocks for interior and exterior wall construction. Just
1/8 inch mortar bed is needed to adhere the products. This extremely
thin joint prevents heat loss and speeds installation. For best results,
apply Thin-Bed Mortar with our notched
trowel. Choose a trowel the same width as the block.
The exception is the first course of AAC. Conventional Type N mortar
must be used to install the first course on the footer or slab. This
is because concrete footings and slabs are never completely level,
and this one thick mortar joint is used to ensure that the first course
will be extemely accurate.
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SafeCrete AAC can be finished with stucco, acrylic finishes, brick,
stone, siding, or approved paints. On the inside of the building,
AAC may be finished with sheetrock, plaster, stucco, wood panel or
tile. Free consultation, color matching, and installer recommendations
available.
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No. Autoclaved aerated concrete is the European construction method
that EIFS imitates; however, construction and performance are entirely
different. EIFS consists of layers of polysterene insulation board,
mesh, and base coats followed by an acrylic top coat. AAC is more
practical, efficient and durable than EIFS:
- AAC requires no surface preparation.
- AAC requires no mesh.
- AAC employs natural, mineral-based products.
- AAC is termite resistant.
- AAC is breathable.
- AAC prevents moisture build-up, thus there is no peeling or rotting.
- AAC is virtually maintenance-free.
- AAC is water resistant.
- AAC does not burn, melt, or off-gas
- AAC is typically less costly than EIFS systems.
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Absolutely. Gypsum board or sheetrock may be attached directly to
AAC walls with construction adhesive and screws, or it can be attached
to furring strips. Please note that AAC should be dry before the sheetrock
is applied. Customers who prefer not to use sheetrock can purchase
a mineral based finish from SafeCrete.
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Any commercially-available roofing system may be used. When AAC roof
panels are installed flat or near flat, they are typically covered
with a membrane system such as built-up or EPDM. On a pitch, the panels
are often covered with shingles, tile or concealed fastener metal
roofs.
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All autoclaved aerated concrete floor systems should be finished.
Common commercially-available products such as carpet and pad, marble,
ceramic tile, wood flooring, and industrial surface treatment may
be used. SafeCrete supplies self-leveling toppings and other products
to be used indoors and out.
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The following chart addresses temperature guidlines. Please note that
these limitations are related to the thinbed mortar, not AAC itself.
Thus the requirements are not applicable when installing AAC panels
without mortared joints.
Provisions for work in progress
| Condition |
Requirement |
| Ambient
temperature above 40° F (4.5° C) |
Normal
construction practice. Cover stored materials. |
| Ambient
temperature below 40° F (4.5° C) or temperature of units
below 40° F (4.5° C). |
Heat
mortar materials to produce mortar temperatures between 40°F
(4.5° C) and 105° F (40° C) at time of mixing. Maintain
mortar above freezing until used in masonry. If units have a temperature
below 20° F (-7° C), heat to above 20° F (-7°
C). Remove visible ice from units. |
| Ambient
temperature is between 25° F (-4° C) and 20° F (-7°C) |
Heat
masonry under construction from both sides. Install wind breaks
when wind velocities reach 15 mph (24 km/h). |
| Ambient
temperature is below 20° F (-7° C). |
Provide
heated enclosure for masonry under construction and maintain temperature
above 32° F (0° C) within that enclosure. |
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Sometimes. The primary ingredient in the chemical reaction needed
for autoclaved aerated concrete production is silica. The silica and
other raw materials combine to form Tobermorite, a manmade version
of a naturally occurring mineral. This gives AAC its unique strength-producing
crystalline structure. Silica is found in many sources, such as sand,
copper mine tailings, volcanic ash, and fly ash. SafeCrete products
are made with locally sourced materials and may contain sand, fly
ash, copper mine tailings, or some combination.
Fly ash blocks are light gray in color, whereas sand-only blocks
are white or tan. Autoclaved aerated concrete made from copper mine
tailings is pink. Since AAC is nearly always finished with stucco
or some other exterior application, color of the product is irrelevant.
The color that matters is "green."
Fly ash makes a "green" product "greener."
- Fly ash is reclaimed from coal combustion. We prefer to see a
product re-used rather than sand mined.
- Fly ash saves electricity during AAC production. Fly ash particles
are tiny and round, with the consistency of talcum powder. Thus,
fly ash does not require the 1000 kw ball mill that must be used
to grind sand to the proper consistency.
Please note that all SafeCrete Manufacturers must comply with the
same standards (ASTM, NER, UL), so the end products perform the
same in regard to strength, fire resistance, sound absorption, and
other design considerations.
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Raw Materials consist of Recycled Post-Industrial Waste
Up to 70% of the raw materials in SafeCrete AAC is recycled content.
Reclaimed fly ash or copper mine tailings is a main ingredient in
some regions. Reclaimed gypsum is also used in the process.
Non-polluting Manufacture
Autoclaved aerated concrete manufacturers use a closed-loop manufacturing
process, so that nothing is ever released other than clean steam.
Product trimmings, slurry and water are reprocessed, and steam is
reused whenever possible.
Resource Efficiency
The end product is approximately 80% entrained air and 20% mass.
Thus 5 parts AAC are produced from just 1 part raw materials.
Low Energy Consumption throughout Lifecycle
The total energy consumption to produce AAC is 1/3 to 1/2 that of
comparable building materials. When installed, AAC results in tremendous
energy savings for heating and cooling the building. In fact, the
fly ash used in AAC saves more energy in that state, than it produced
when the coal was burned.
Healthier Indoor Air Quality
AAC products are an excellent choice for the chemically sensitive
because autoclaved aerated concrete does not offgas. AAC does not
promote the growth of mildew and mold, and cannot be infested by
termites. Rats and other pests find no home, since there is no cavity
in an AAC wall. Pestacides can be reduced, and the occupants can
breathe a little easier.
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Accessories:
Thinbed mortar
Block patch
Repair mortar
for panels
Tools:
Saw
with wide teeth
Notched
trowel same width as block
Rasp
Bucket for mortar
Paddle mixer extension
3"
or 4" drill bit with extension
or core
drill
Equipment Rental:
You must supply a forklift to unload the material. Capacity should
be at least 1.5 tons.
If you plan to use SafeCrete for ledges, quoins and other fancy
trim work, a large bandsaw
is helpful.
If you are installing jumbo blocks, you will need a mini-crane.
If you are installing floor panels, you will need to rent a crane
and also lifting
equipment.
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The lead time for standard products is typically one week. Lead time
for custom products such as special length panels may be up to 12
weeks. In either case, we encourage you to contact
us early on. We will be pleased to assist you with estimating,
choosing appropriate products, and locating other resources for your
project.
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As a part of our mission to make AAC construction available nationwide,
SafeCrete has negotiated agreements with every US manufacturer of
AAC products. These agreements allow us to offer standardized pricing
and reduce your shipping costs. Our marketing headquarters are located
on site at one of these production facilities. Please call in advance
to arrange a tour.
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Yes, vertical cores are an integral part of the AAC
block system and are required. Cored blocks may be used for this purpose,
or installers may core standard blocks using a 3"
or 4" drill bit kit or core drill. Rebar is inserted into
these cores and is tied to both the foundation and the rebar in the
bond beam. Cores are then filled with conventional concrete grout.
Vertical reinforcement cores lend additional strength to the AAC structure,
and are required in all regions. Minimum code requirement is one reinforcement
core on either side of each opening, in each corner, and wall intersections.
For more information see
ICC (code for AAC construction).
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SafeCrete materials are environmentally-friendly in
a number of ways (see above), and LEED does recognize this. Please
note however, that LEED certification is based on the construction
project, not a single material.
LEED recognizes aerated concrete products in the following
manner:
- Recycled content (applicable to AAC blocks containing fly ash
and copper mine tailings)
- Reduced energy consumption
- Locally sourced products (if applicable to project)
- Locally sourced raw materials
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