Old House Remodeling Series, Part 2
Last month we began the Old House Remodeling Series with an introduction and comments about preserving historical houses. In this article we will discuss inspecting, maintaining and repairing foundations on older homes. (See related post: Sewer Line Inspection and Repairs)
Inspection Repairs Costs
There are three key aspects to checking for foundation problems in older homes:
- The type of foundation – brick, stone or concrete
- Structural movement due to expansive soils
- Settling and/or efflorescence from poor drainage
Architectural Types of Denver Historic Houses:
- Victorian Historic Homes 1885-1905
- Denver Square / Four Square 1900-1910
- Craftsman / Bungalow Style 1910 – 1929
- Cottage Style 1925-1939
- Tudor Style 1929-1940
Masonry Foundation in Historic Houses
In historic districts of Denver, houses constructed between 1890 and 1940 are often built on “spread footings,” which are foundations made of brick, stone or concrete that form the base of the exterior walls. The weight of a house rests on its’ foundation, and the structural integrity depends on the design and maintenance of the foundation system.
The oldest homes in Denver, the pre-1900 Victorians, are usually built on brick or stone foundations. Poured concrete is a much better foundation material, but was not commonly used until around 1925, after which bungalows, Tudors, and then ranch homes were built. Of particular concern are foundations with “sand brick,” as it deteriorates significantly over time.
Sedimentary and Expansive Soils
Soils are another important aspect of looking at foundations. Some soils are sedimentary (sandy) in composition, which are generally more stable compared to the expansive clays, such as Bentonite and Montmarillonite. Foundations built on expansive soils are prone to bulging and heaving and sometimes total failure.
Evidence of structural motion is easy to detect in houses of masonry construction. Exterior walls, which bear the heaviest load from the roof, typically will settle downwards, producing stress along the walls that run at right angles to them. You will see cracks formed in the walls, and around windows and doors in predictable patterns. This is known as “crowning.”
The best place to begin looking for potential foundation problems is to walk the perimeter of a house and observe the drainage systems. Check to see if the gutters are in good condition and whether the downspouts direct water away from the foundation. Observe the “slope” of the ground next to the house. Broken concrete near the corners, missing gutter extensions and any place that water can collect and drain down the sides of the house are signs of potential trouble.
On the interior of the house, look for cracks over windows and doors and check how smoothly they operate. Check for slab cracking in the garage, basement or front porch; listen for squeaky wood floors; and separation of floor boards. A 4 foot bubble level is an excellent tool for checking levelness of floors and trueness of the interior walls.
Efflorescence in Basement Walls
In many cases moisture problems will also be easy to detect in the basement walls. There will a weakening in the plaster and/or dusty deposits of chemicals that have traveled through the foundation with the water and dried on the surface. This is called “efflorescence.”
While the foundation problems discussed are commonplace in older homes, most do not threaten their structural integrity. A good contractor can fix most foundation problems, and the cost to make the repairs will range from a few thousand dollars to more than thirty thousand. Qualified home inspectors will be able to identify problems, but severe issues warrant a professional engineer’s opinion. There are a few inspection companies in Denver that specialize in older structures; one of them is Coyle Home and Building Inspection Engineers.
First Step Old House Foundation Maintenance
- Establish a slope of approximately 5 inches in the first 5 feet away from the home by adding add fill dirt.
- Examine actual drainage of water through the gutters during a rain storm and repair clogged or leaky gutters.
- Add longer down spout extensions to get the water moving away from the foundation walls.
- Do not plant anything that requires watering next to the house.
Stay tuned for the next article in the series, Old House Roof Types on historic homes, which will discuss pitches, materials, common problems and repair costs. Please feel free to ask questions or make suggestions for future articles about historic home renovations in the comments sections below, we will reply or respond.
About the series: Old House Remodeling Series is about buying and remodeling older homes for both investors and owner occupant buyers. The information is relevant to home owners and house enthusiasts in neighborhoods with housing stock built between 1890 and 1940. Our office also follows how buyer or owners can get grants for historic home renovations.
To be a certified renovator, contractors are required to take eight hours of training from an “accredited” service. Two hours must be “hands-on training.”
