Let’s talk room additions.
Through out the years, many times I’ve encountered buyers and owners of homes that some how end up in a costly predicament due to room addition(s).
The predicament of the room additions can be cumbersome. As you know room additions come in many forms; garage conversions, expanded living rooms, additional bedrooms, media rooms, etc. With the best intentions to increase square footage for re-sale value or to add comfort to the home, if the addition is not planned or constructed well, chances are, in the plastic soils (Vertisols) of Texas and its propensity for volumetric change, the owner will incur costs to amend or control the addition(s) settlement.
The two scenarios I bring to the fore front are more commonly found with foundation movement. First are the room additions constructed of a concrete slabs. The second in line are those constructed of a pier and beam and/or pier and post construction.
Slab additions most commonly found for room additions come in two categories. The first type is constructed with all new material with absence of any existing monolithic slab incorporated into the new pour. The second type, utilize existing monolithic slabs, such as a back or front porch and are built around or on the existing concrete.
The first of the two slab additions are straight forward and usually perform the best if designed with site conditions and performance in mind. The second of the two slab additions are more susceptible to problems. Slab additions built around or on existing material such as a concrete porch or patio usually involves adding a load to the perimeter of which was not originally designed to carry the new load. Coupled with perimeter load issues are tie-in issues. This is where the existing porch or patio is tied into any new concrete by means of steel dowels. These factors in conjunction with poor drainage, plastic soils and water leaks or plumbing leaks prove to be a formula which enables this type of room addition to fail.
Pier and Beam and/or Pier and Post room additions are, for the most part easier to maintain if differential movement occurs. This is due to the ease and access to the supporting members of the addition, unlike slab additions that are built on grade, around porches or patios. However, if the pier and beam addition is built without adequate access to the understructure it can result in more costly adjustments if needed.
When purchasing a home with room additions or building a room addition for added comfort, consult a trusted, certified contractor to inspect, design or construct the addition. As the ol’adage promotes …an ounce of prevention is worth a pound of cure.