Roofing
| >>Final
grade | Soffit and
fascia | Electrical
and gas laterals | House
wrap | Masonry |
Stucco | Siding
| Exterior concrete
| Exterior paint
| Foundation parging
Final grading and concrete preparation usually takes
place at the first part of the exterior (phase 4)
phase. Typically the grading is done with a combination
of the following: Backhoe, skidsteer (aka-Bobcat™),
front loader or track hoe. Suitable base material
(Gravel, road base etc.) needs to be brought in where
walkways, driveways and concrete slabs are planned.
According to the Code the soil must slope away from
the foundation @ 5% for 10'. Another important factor
is that water runoff must run from your property to
the street or public property. Driveways and walkways
need to have a slight slope to drain water. Some cities
require a grading plan as part of the permit application.
This is required to ensure that your water runoff
doesn't end up flooding your neighbors property. It
may be necessary to consult an engineer/landscape
architect to design a drain plan for your project.
It is important to know the elevation at which the
concrete will be placed. In most situations it will
be obvious. For example, the driveway will need to
be flush with the sidewalk edge. A transit or laser
level may be used to determine the elevation of patios
or slabs. Once the elevation of a slab is determined,
the soil must be excavated down the thickness of the
slab plus any fill. Remember it is a good idea to
slope the slab away from the house slightly (2-3%)
to alleviate standing water.
If part of your construction documents includes a
landscaping plan now is a good time to get the excavation
contractor and the landscaping team together. Excess
dirt from the excavation can be used for landscaping.
Time and effort can be saved if the excavator and
the landscaper work out a grading plan that works
for the Grade and the landscape plans. Even if you
don't have a landscaping plan, it is a good idea to
bring in topsoil (4-6"deep, if conditions warrant)
at this stage. You will then be ready to plant as
soon as the construction is complete.
The Description of Materials document should specify
the type, compaction requirements, and depth of gravel
required under exterior slabs.
In poor compactable soils (clay, silt and sand) compacted
road base is used to give the slab extra strength.
Where soil strength is not a concern, pea gravel is
often used because it give does not require compaction.
The gravel is place to a depth of 4-6" inches
in most circumstances. Ask your concrete contractor
what he recommends for your particular area.
Whether you have plans now for an exterior irrigation
system or exterior lights it is a good idea to plan
for them. If you have a landscaping plan the landscapers
will need to place any sprinkler pipe and electrical
wires underneath exterior concrete slabs where they
cross before concrete is placed. If you don't have
detailed plans at this point (most people don't) Place
plastic pipe underneath under the walkways and driveways
at strategic points. This will allow you to feed pipes
and wires underneath the concrete without having dig
below or cut the concrete away from above. Use 2-3"
plastic pipe to accommodate sprinklers pipes and 1-2"
pipe for exterior wire.
The final grade and concrete preparation can be done
during this phase or at the end of the project. Since
there is sufficient time now it is a good idea complete
it as soon as possible. If the weather will improve
as you get closer to the end of the project you might
decide to wait, as grading is difficult when the ground
is frozen.
It is important that the final grade is done by experienced
excavators especially if you schedule the final grade
at the end of the project. It's not to uncommon (in
our experience) for inexperienced operators to damage
siding, brick or stucco while completing the final
grade.
