ADU Construction in Diamond Bar, Roof Down to Footing
Diamond Bar ADUs planned from the roof drains down to the footings, with runoff led away from the slab edge and every wall anchored to its foundation.
Every gallon of rain that leaves a Diamond Bar ADU roof ends up beside its footing unless something carries it off. We pitch the roof toward one side, hang a gutter along that eave and send each downspout into solid pipe that discharges at a dry well or toward the street where the city allows it. Soil kept at an even moisture around the slab edge stops the foundation from heaving or settling unevenly, which protects every anchor bolt above it.
Roof framing that carries its own load
In an earthquake the roof sheathing acts as a horizontal diaphragm. It gathers the sideways force from the mass overhead and hands it to the shear walls, which pass it down through hold-downs into the concrete. Nailing along the sheathing edges is what makes that transfer work, so the engineer specifies the spacing and the inspector counts it before any roofing goes on. Rafter ties or truss clips at every bearing point keep the roof seated on the walls. For an inland lot under hard sun, a light-colored cool roof surface also keeps heat out of the rooms below.
Shaping the ground around the unit
Before the slab is formed, the pad gets shaped so finished soil drops away from each wall. Splashback at the base of a wall wets the sill plate and stains plaster, so a band of crushed rock and a weep screed at the bottom edge of the stucco keep the framing dry. If the lot slopes, a swale on the uphill side catches surface flow before it reaches the unit. At the final inspection, the finished grades are compared with the approved drainage plan, and we build to that plan from the first cut of the pad.
About our adu construction serviceEverything we do in Diamond Bar
ADU Construction in Diamond Bar: questions
A slab-on-grade ringed by continuous reinforced footings is the standard base, sized by the engineer to the soil found on the lot. Anchor bolts and hold-downs cast into that concrete tie the walls down. If a soils report turns up expansive clay, deeper footings or a layer of select fill and a moisture barrier under the slab may be specified.
Whatever the trench beside the garage wall reveals decides it. Old footings are judged on depth, width and whether any reinforcing steel runs through them. One that meets the engineer's requirements for a habitable room stays, and the walls get new sill anchors and plywood shear panels. One that does not is replaced, section by section, under the walls chosen to resist lateral load.
Eligibility rests on two limits, a single story and a floor area no larger than 500 square feet, and a garage conversion counts as readily as a new detached or attached unit. On a Diamond Bar lot the site plan earns its keep by marking where roof water leaves the property. A two-story or bigger unit is priced in writing once we have seen the lot.
More we build in Diamond Bar
Book an inspection in Diamond Bar
Describe the house and what it needs. We look at the structure first and send the quote in writing.