Basic Differences Between Historic and Modern Homes
Before:
After:
Your house is one of the most important investments you will make in your lifetime. Just like your automobile, your historic home needs regular upkeep and has needs that are unique to its make and model. Fortunately, the exterior materials on your historic house are locally made and long-lasting, and are typically much more durable than modern building materials.
Historic Houses
- Varying materials, such as wood, masonry, and metals, carefully matched to one another and a particular locale and/or climate
- Materials can last for many decades when well maintained
- Structural masonry of varying hardness due to placement in a kiln
- Flexible mortar with high concentrations of lime
- Permeable construction designed to absorb water and then readily release it through evaporation
- Energy efficiency and comfort controlled naturally through use of building materials, openings, and building placement
- Thick, heavy building materials with low levels of artificial insulation
Modern Houses
- Synthetic materials that are standardized, pre- assembled, and chosen from national producers without regard for locale and/or climate
- Materials have an average lifespan of 10-25 years when well maintained
- Veneer masonry of extreme hardness due to firing at much higher temperature
- Rigid mortar with high concentrations of cement
- Emphasis on waterproofing to prevent water penetration. Once trapped, water cannot evaporate
- Energy efficiency and comfort controlled by automated temperature control systems and insulation
- Thin, lightweight building materials with high levels of artificial insulation
Maintenance Tips:
- If you purchase a historic home where repairs have been delayed, you may notice serious conditions such as a cracked building wall or a shifted foundation, which require quick corrective action.
- For serious problems hire professionals, such as a structural engineer with experience working on historic buildings, to help you develop an appropriate course of action. Historic Denver, Inc. maintains a list of historic preservation architects, engineers, and contractors.
- If possible, perform annual inspections to make sure that everything is in working order. An examination of roof, chimney, gutters/downspouts, exterior walls and porches, windows, foundations, doors, attic and basement will identify problem areas, and needed repairs.
- An owner can then take small actions – such as painting a wood sash window or emptying gutters – to avert a more serious problem later.
- Regardless of the type of maintenance work needed, consider the building’s historic materials and its character-defining features.
- For more resources on maintenance including inspection guides and checklists, see the Caring for Your Home section on the Resources page.
MAINTAINING BRICK EXTERIORS
Exterior walls, banding and raised patterning, window sills/lintels, chimneys, and foundations.
Maintenance of Brick Masonry:
The early bricks in Denver were low fired. In Curtis Park the bricks on the old homes are soft, sandy and easily crumble. Unless you are using special techniques, DO NOT drill, nail or screw into the soft brick . You can find more info on old brick here.
While brick walls and features can last indefinitely, they can deteriorate and need repair. If bricks are spalling (or flaking), cracking, loose, missing mortar, have a salty powder coating, or are otherwise discolored, chances are your bricks need maintenance. Some problems may be caused by prior inappropriate repairs, such as the use of a hard mortar with a high Portland cement content that can prevent your historic building from breathing or shifting naturally. Excessive cleaning or sandblasting of the brick that can remove the hard outer surface of the brick.
Brick Masonry Maintenance Tips:

- DO repoint joints using a soft mortar with a high lime content to match the original mortar in color, texture and composition.
- DO use the gentlest possible means of cleaning historic brick, and test all products in an inconspicuous location.
- DO hire a mason who specialized in historic buildings to repair cracked, spalling, loose or discolored bricks.

- DO NOT drill or nail into the exterior brick.
- DO NOT paint or stucco bricks to cover up brick problems.
- DO NOT clean with chemicals, apply high pressure water blasting, sandblast, or use masonry sealants.
- DO NOT use of ready-made mortar mixes with high content of Portland cement.
Before replacing mortar, cleaning, painting, stuccoing or using masonry sealants, contact a mason, architect, engineer or contractor who specializes in historic buildings if possible. These repairs are best left to a specialist. Also, refer to resources on historic brick.
MAINTAINING STONE TRIM
Foundations, window sills/lintels, banding or other decoration, and occasionally exterior walls.
Maintenance of Stone:
The soft limestone and sandstone masonry commonly found in Curtis Park can have many of the same issues as brick, such as spalling, cracking, water penetration or loosening pieces. Stone used in foundations can often bulge or sink if water is not properly draining away from the foundation on the building site; sandstone in particular can deteriorate quickly with sustained water exposure. Drainage issues and wear-and-tear can also lead to historic stone features such as wall banding deteriorating and spalling from the building wall. The stone details on Curtis Park historic buildings are invaluable, making appropriate repair even more important, since these features can be very difficult and expensive to replace.
Stone Masonry Maintenance Tips:

- DO use the gentlest possible means of cleaning historic stone, and test all products in an inconspicuous location.
- DO re-anchor a loose or detaching stone feature.
- DO remove, turn and re-mortar damaged stone block

- DO NOT clean stone with chemicals, apply high pressure water blasting, sandblast or cover stone with masonry sealants.
- DO NOT use ready-made mortar mixes with a high content of Portland cement.
- DO NOT paint over limestone or sandstone elements to cover up problems.
- DO NOT remove an original stone feature.
Before deciding a course of action, contact a mason, architect or contractor who specializes in historic buildings. These repairs are best left to a specialist. Also, refer to resources on historic stone.
Maintaining Wood Features
Wood siding, windows and doors, front porches, foundation aprons and roof cornices, roof gables, banding and trim.
Wood Maintenance:
The wood in a historic window sash, for example, is almost always of higher quality and durability than a new wood window sash, making reuse and rehabilitation a good choice. Common problems with exterior wood is its susceptibility to insects, mold, cracking, weathering and decay. Most exterior wood originally had a protective coating, such as paint or stain. When this coating wears off or is removed, wood can deteriorate quickly when exposed to the natural elements.
Exterior Wood Maintenance Tips:

- DO keep wood away from the ground, and vegetation off of wood surfaces.
- DO check regularly that roofs are flashed and gutters are functioning well to avoid water draining onto wood roof cornices and porches.
- DO use an architectural epoxy or make a Dutchmen repair with compatible wood when only a part of an original wooden feature, such as a small piece of a wooden window sash, is deteriorated.
- DO replace just the damaged part of a rotten wooden element in kind, such as a porch rail or window muntin, and retain the remaining wooden feature as is.

- DO NOT let exterior wooden elements deteriorate or rot, or go without stain or paint for prolonged periods.
- DO NOT remove historic wooden windows when they can be repaired.
- DO NOT remove historic wooden porches, windows, cornices or other decorative elements without documenting what is being removed, and having a replacement plan in place. Demolition and removal require permits.
This web content was added in 2019, and is accurate to the best of our abilities. Contact Denver Landmark Preservation for the most up-to-date and accurate information on the city’s design review and permit requirements.