Question: What is Scaling Concrete? (Figure 1)
|Question: What type of pier should be used for my foundation repair? |
Answer: The Denver area and surrounding counties in Colorado have expansive soil problems. We have found that when a structure is built on this type of soil a drilled concrete pier properly designed by an engineer with the proper steel installed, locked deep into bedrock will resist the skin friction uplift of expansive soil. However, the void area in between the piers under the foundation wall must be sufficient and stay in tact.
Question: What causes soil to swell?
In a sample of pure montmorillonite the plates may expand so much that the sample increases up to 15 times its original volume. While most montmorillonite soils will not expand over 35-50 percent, the pressure and movements created on a building foundation or floor by this tremendous volume increase are responsible for most swelling soil damage.
|Question: What type of material should I use under my landscaping to stop weeds? |
Answer: Do not use plastic under the landscape because it traps moisture. Use a landscape fabric that allows the soil to dry. It is also important the soil slopes away from the foundation wall at least a minimum of 1 inch per foot, or more if possible. Most engineers prefer 10 inch drop in 10 feet sloping away from the foundation.
Question: Does it hurt if water stands behind my landscape border edging around my house?Answer:
Allowing water to stand behind your landscape border edging could cause problems as pictured in figure #3. When the hole in your lot was excavated for your foundation to be installed, it was made larger by 2-5 feet around all sides. This additional area allows room for the workers to place and remove the foundation forms as needed. After the foundation was constructed and water proofed this 2-5 feet area was then backfilled. Over time this area has a tendency to settle and compact. This backfilled area is porous allowing water to seep to the bottom of the foundation.
Question: What kind of landscape border edging should be used?
Answer: Any edging may be used if drilled or modified with 3/8 inch or larger drain holes every 1-2 feet, in the center width of the edging. This will allow the water to bleed through the edging. Normal edging is usually 3-4 inches in width.
Question: If I get water in my basement why canít I just install a sump pump only?
Answer: If your house is on caissons and the void under the foundation wall is still somewhat in tack it may work for a while. If this void closes up it will only pick up water immediately around the sump pit and pump area only. A sump pump and pit is only to collect water and pump it out of your basement. With out an interior drain system there is no way for the water to get from the opposite side of the basement to where the sump pit and pump are. A proper drain system design is very important. Please see information listed under Water Problems Page (Figure 3)
Question: Should I be concerned if I start to see cracks in my foundation wall or retaining wall?
(Figure #4) There is a reason why cracks appear in concrete foundation walls or retaining walls. You may have a problem developing. Sometimes these cracks donít worsen and sometimes they happen so slowly you donít notice the subtle progressive change. It is best to have this problem looked at and monitored by an experienced structural contractor and a professional structural engineer.
|Please contact Alltypes Concrete & Construction, Inc. if you have additional questions regarding Engineering or repairs.|