A typical home inspection includes a thorough check of all the major systems and structural elements of a home.

But it is the big ticket items – typically the sort of thing that would cost the homeowner $10,000 or more to repair or replace – that potential homeowners need to pay particular attention to, and be sure to ask their home inspector about during the process.

Here are five questions that all home buyers should make sure are answered during their home inspection.

How old is the roof?

The life expectancy of a typical residential roof depends on a number of variables, including the roofing material used, the local climate and the size and shape of the roof surface itself. As a general rule, a 3-tab asphalt shingle roof should last 20 to 25 years, thicker architectural asphalt shingles 25 to 30 years, a metal roof 30 to 45 years and concrete tiles 35 to 50 years. While replacement costs vary widely depending on the size, season, and type, rough budgetary costs for a shingle roof can range between $7 and $10 per square foot.

Is the home in an expansive soil zone?

Expansive soils are those that contain specific minerals that have a higher tendency to expand when they absorb water and shrink as they dry out. This movement can generate tremendous force, causing home foundation or basement damage and other structural problems where they are present. Homes built in expansive soil zones need to be designed to minimize potential moisture content changes and insulated from soil volume changes.

What is the condition of the heating system?

With furnace replacement costs ranging from $2,500 and up, it’s certainly worth knowing the condition in advance of purchase in the case a full replacement is needed within a few years. The average life expectancy of a heating system varies depending on type, with forced air furnaces lasting between 15 to 25 years and hot water boilers lasting 20 years or longer with proper maintenance.

Any structural concerns?

Aside from the fact that foundation repairs can be very costly, any visible structural issues with a home often point to even more significant concerns. What’s more, reselling a home with a repaired foundation is often more difficult, for this same reason. If the foundation has shifted, it is well worth asking the home inspector, who is preferably also a licensed structural engineer, what else in the home was damaged in the process? Significant foundation repairs often consist of installing vertical steel supports, called piers, under the foundation to support it on a more stable layer of soil. Horizontal anchors can also be installed through the foundation wall to provide lateral support to foundation walls that are displaced inward.

Should I get a sewer line inspection?

Although not something that home inspectors typically do themselves — this work involves a specialist plumber — sewer line inspections are recommended as part of most home inspection, for the simple reason that a sewer line repair can cost as much as $30,000 depending on depth, scale, and location of repair.