Fireplaces fall into two categories. The first being “full masonry.” this type of fireplace is constructed with a masonry flue, exterior veneer and interior firebox. The second is “prefabricated”, having a metal pipe chimney and a manufactured metal firebox.
1. Common Defect or Problem – Fireplace or chimney does not draw properly.
Performance Standard – A properly designed and constructed fireplace and chimney shall function properly. It is normal to expect that high winds can cause temporary negative draft situations. Similar negative draft situations can also be caused by obstructions such as large branches of trees too close to the chimney.
Builder Repair Responsibility- Builder will determine the cause of malfunction and correct, if the problem is one of design or construction of the fireplace.
Craig’s Comments:Good chimney specifications and details exist to create well-drafting chimneys, under normal circumstances. Chimney and fireplace design should include roof slopes and heights. Unusual circumstances that might make a chimney draw poorly or not at all are large range hoods, attic fans, and other mechanical devices that pull a lot of air out of the house. These devices need make-up air, and will pull air down the fireplace if sufficient other air is not available.
In any case, the chimney should draw properly when the room is depressurized to -5 pascals with respect to outside. If it does not, the chimney/fireplace needs modifications. If a ventilation fan or other mechanical ventilation system can depressurize the room to more than -5 pascals, a source of make-up air needs to be added, the fireplace needs to be made sealed combustion, or the mechanical ventilation system needs to be removed.
5. Common Defect or Problem –Cracks in chimney and fireplace caps.
Performance Standard – Chimney and fireplace caps should be checked periodically by the owners for hairline cracks in the concrete and brick, and especially next to the flue. These cracks are caused by shrinkage and severe weather conditions and should be caulked with an elastic type caulking compound or tuckpointed with mortar or cement. Failure to do this could result in moisture getting into the chimney, freezing and cracking the flue material or the face of the brick or stone.
Builder Repair Responsibility – None, unless crack exceed 1/8″ in width. Builder will then tuckpoint.
Craig’s Comments: Cracks in chimney caps are quite common. This is a maintenance item. Metal chimney caps and rain shields can help reduce water entry, as long as they are made water tight. Chimney caps should be sloped and extend over the edge of the chimney, and drain water away from the chimney itself.
6. Common Defect or Problem – Fireplace fans are noisy.
Performance Standard – Fans will make some noise due to the location of their installation but should not be excessively noisy. Fireplace fans are covered by a one-year manufacturer’s warranty. Noise level is not to exceed manufacturer’s acceptable noise level.
Builder Repair Responsibility – Builder to inspect and repair if fan is touching any party of fireplace.
7. Common Defect or Problem – Cracks in mortar joints of brick or other masonry walls or veneers.
Performance Standard – Small hairline cracks due to shrinkage are common in mortar joints in masonry construction. Cracks greater than 1/8″ in width are considered excessive.
Builder Repair Responsibility- Builder will repair cracks in excess of Performance Standard by pointing or patching. These repairs shall be made at the end of the first year of the warranty period. Owner should be aware that some variation between old and new mortar color will occur.
Craig’s Comments: Do not confuse small hairline shrinkage cracks with settlement or movement cracks. Cracks that develop because of settling or movement of the structure are a concern, especially if they continue to grow.
8. Common Defect or Problem – Chimney separation from structure to which it is attached.
Performance Standard – Newly built fireplaces will often incur slight amounts of separation. Separation shall not exceed 1/2″ from the main structure in any 10′ vertical measurement.
Builder Repair Responsibility – Builder will determine the cause of separation and correct if standard is not met.
Craig’s comments: Brick, block and stone chimneys should be supported by the ground, not the house. They should stand on their own, but be connected to the house mainly through caulking and trim. A wood house may shrink slightly during the first year or so as it dries out, and may separate a small amount (maybe ½”) from the chimney. But all movement should stop in the first year or so, and this shrinkage movement will be pretty uniform all the way up the chimney. If the gap at the upper part of the chimney is larger than at the bottom, the gaps continues to grow for more than a year, or the gap gets larger than ½”, something is probably moving too much.