Foundation Preventative Measures for New ConstructionThere are several steps that should be considered before building a new home that can potentially reduce or eliminate most future foundation related problems.
If the land is virgin, meaning it has never had a structure built on it before, there are several important questions you need to consider:
- How many trees were removed and where were they located in relation to where my new slab will be?
- Was there a ditch, ravine, or other low area that was filled in under my site?
- What type of fill material was used, and how long ago was it installed, and has it had time to settle in?
- Where is the high ground, with good water runoff capabilities, and was the high ground artificially created with fill dirt?
Topographical maps are sometimes available through the Army Corps of Engineers. They will show your lot at various times in the past, and what was located there. If the property had a home or other structure on it in the past, there are other important issues related to that particular situation, including:
- Questions 1 – 4 above.
- Was the entire foundation and sewer system completely removed?
- Had the previous foundation ever been repaired, and which underpinning method was used. Is there a drawing showing the location of any existing piers/pilings that were not totally removed? This is extremely important information to know when deciding where to locate the new slab, and any new underpinning system.
Any builder or developer should know the answer to these questions, and should provide all documentation, and a full set of maps and blueprints for all phases of the new construction.
Another very important consideration for new construction is the moisture content of the soil. If the ground is too wet, then on the day the new concrete slab is poured, it will settle very quickly when the ground dries out. If the ground is too dry when the slab is poured, the slab will potentially “Heave” when it rains. Potential Vertical Rise (PVR) testing, and Placidity Index (PI) calculations, are highly recommended before pouring the slab. The link to Geotech Engineering can be found in the side bar on this web site, and they provide this service.
Another important consideration when locating the new foundation site is the proximity to the existing trees, and any trees that may be added later on. Designing and installing Root Barriers should be part of the total building plans, and installed prior to sprinkler systems and landscaping. Root Barriers need to be located a specific distance from the tree, to prevent harming or killing the tree. To calculate a reasonable distance, measure the circumference of the tree, about two feet up from the bottom. Take that number and triple it. Add two feet to that, for the minimum distance out away from the edge of the foundation where the root barrier will be installed.
There are many ways to construct a slab foundation which will reduce the likely hood of ever having foundation problems. Besides the systems mentioned above, constructing thicker slabs and grade beams, with adequate reinforcing steel, are critical. Moisture barrier protection under the slab is also important. Hot-mopped tar paper or one-ply systems are much better than simple plastic sheeting. An independent engineer should be consulted to review the entire set of plans submitted by the builder. He can make recommendations on improving the design and review other facets of construction such as sewer and plumbing systems, mechanical and electrical systems, and all framing and structural components. Having an independent voice can often spot potential problems before they arise. The Foundation Performance Association has over 100 engineers to choose from.
Builders Piers or Pilings:
Custom homes are often constructed with piers or pilings from the start, but there are several questions to consider:
- Once the type of soil and load to be carried is calculated by the engineer, the best foundation support system can be determined; Piers or Pilings?
- What is the purpose of the underpinning? Settlement or Heaving prevention; Or both?
- Should the pilings or piers be connected to the foundation?
- What spacing to use for exterior perimeter pilings or piers – 8 ft on center, or less?
- Should interior pilings /piers be installed, or exterior only, and are there ever additional charges?
- What type of warranty will I receive and who will issue it?
The builder, or the Foundation Repair Contractor?
How Long will the warranty be good for?
Whether you have an existing home, a new home, or are considering building a home, please call one of the highly trained professionals at Dura Pier for a free, no obligation consultation, and if needed, a free inspection. By correcting problems while they are relatively minor, or possibly just preventative in nature, you will protect your most valuable asset, and keep your peace of mind.