Newport foundations are at high risk of damage, mainly due to geologic and climatic factors. We’ll explain each of the typical culprits of foundation problems below and include information about how each can compromise your home’s structural integrity.
The dirt throughout Oregon is widely varied, but the Bandon, Lint, and Nelscott soils underlying most of Newport have an abundance of clay particles in them, making the ground expansive.
Expansive soil is problematic for construction for several reasons, the most dangerous of which are related to its capacity to shrink and swell with changes in moisture content.
The most significant damage in Newport often occurs when the ground around your home gets wet and expands. Runoff from rainfall soaks into the ground and gradually increases the soil’s volume.
The more water that seeps between the tiny clay particles in the dirt, the more the earth swells against your foundation and places excessive hydrostatic pressure on the concrete. Your slab or basement walls can crack under the stress, creating structural damage.
During the summer months, when Newport experiences insignificant rainfall, the moisture in the soil can drain deeper into the ground, leaving the soil surrounding your concrete to dry. Newport’s expansive soil loses volume when it loses moisture, meaning it can pull away from the concrete and leave portions of it without adequate support.
This process can occur unevenly under your house due to the clay content, causing only sections of the concrete to lose support and sink into the earth. Differential settling is a widespread issue in Newport that can cause severe structural damage.
The clay in the soil also absorbs and retains water readily, so the ground remains saturated for longer than dirt with better drainage capabilities.
As such, the soil holds runoff against your foundation continuously, increasing the risk of it soaking through pores in the concrete or through foundation cracks. The resulting water damage and moisture accumulation are both prevalent problems in Newport.
Lastly, Coastal Oregon is underlain by cemented hardpan, which is a layer of subsoil that is highly plastic and has exceptionally slow drainage.
This soil layer contributes to saturation above, worsening the hydrostatic pressure on your foundation and increasing the likelihood of water intrusion.
Oregon is well-known for its abundant rainfall, and Newport residents contend with an enormous 76 inches of rain annually. This is nearly 250% of the national average.
The excessive runoff from the above-average rainfall poses two threats to home foundations in the area. First, it keeps the ground saturated almost constantly during the months with heavy precipitation.
This increases the volume of the soil and the resulting stress on your concrete slab or foundation walls. Additionally, the persistently high moisture content in the ground makes foundation leaking more probable.
Residents do get some reprieve from the above-average rainfall from May to September when monthly averages are about a tenth of the rest of the year. The dry period can contribute to differential settling, and the cycling of wet to dry and back again makes hazardous foundation movement more of a problem.
Flooding is a significant problem in Newport for several reasons, all of which are directly related to the above-average rainfall.
First, flash flooding can occur during heavy precipitation because the clay soil and the hardpan in the region drain slowly and often cannot keep up with the runoff. Water regularly pools near the surface during rainfall, and the slopes in the city can cause flash floods to occur.
Stream and ocean flooding can also affect Newport if the rainfall causes the tides to rise. Storm surge is most common in winter when rain is at its peak in the area, and it can create an overflow of ocean or bay water onto the surrounding area.
Flooding contributes to ground saturation, increasing the risk of undue hydrostatic pressure on your concrete and water intrusion.
Earthquakes are a common occurrence on much of the west coast, and Newport, in particular, is at high risk of seismic activity. The significant faults off the coast cause frequent earth-shaking and contribute to ground movement that is so detrimental to home foundations.
Earthquakes are one of the few phenomena that can cause instant structural damage if it shifts soil toward or away from your foundation. They can also contribute to differential settling over time, even if the area only experiences relatively minor quakes.
Lastly, Newport homes are at moderate to high risk of radon, an odorless, colorless gas that is deadly to humans in large quantities.
Radon typically seeps through fissures in home foundations, and while it doesn’t cause damage to the concrete under your home, your foundation should be sealed to prevent the gas from seeping inside.