EIFS or Traditional Stucco: How to Tell, and Why It Changes the Repair

Two very different wall systems get called “stucco” in this metro, and knowing which one is on your house changes the diagnosis, the repair method, the material, and the price.

The two-minute test

Knock on it. Traditional three-coat stucco is cement over metal lath: hard, solid, and unforgiving to your knuckle. EIFS is expanded foam board with a thin reinforced acrylic coating: it sounds duller and softer, and a firm press with your thumb will often leave a slight dent.

Look at the edges. At a window return, a corner, or a control joint, traditional stucco shows a thick cement edge, often three quarters of an inch or more. EIFS shows a thin coating over a much thicker foam layer.

Try a magnet. Traditional stucco usually has metal lath behind it, which a magnet will find. EIFS generally will not give you that.

Look at the trim. Decorative bands, window surrounds, and quoins that are clearly shaped and lightweight are usually foam. Traditional houses get those details in cement over lath, or not at all.

Check the age and style. Traditional three-coat has been used here forever. EIFS and synthetic systems became common in newer residential construction, particularly on decorative details and on some subdivisions.

If you are still not sure, photograph an edge or a return and send it. It is usually obvious from a picture.

How each one fails

Traditional three-coat cracks. It is cement, it shrinks as it cures, and it moves with temperature. It cracks at stress points, it cracks from shrinkage, and once water gets behind it, freeze-thaw delaminates it from the lath. The cracks page and the hollow stucco page cover both.

EIFS does not crack the same way, because the acrylic finish is flexible. What EIFS does is:

• Take impact damage. A ladder, a hail event, a lawnmower-thrown rock, a car door. The surface is thin over foam and it punctures rather than chips.
• Hold moisture. This is the real issue. Where water gets behind the foam through a failed sealant joint, a bad flashing, or a penetration, it can be slow to dry out, particularly in older systems that were installed without a drainage plane.
• Suffer at the terminations. Where EIFS meets a window, a roof, a deck ledger, or grade is where problems start. Sealant joints are maintenance items with a finite life.
• Show damage at the base, where splash-back and irrigation hit it.

Why the repair method matters

A traditional patch uses cement over lath. An EIFS repair uses the manufacturer’s system: foam, base coat, mesh, and finish, matched to the existing texture.

Patch an EIFS wall with cement and you have put a hard, heavy, differently-moving material into a soft flexible system. It will crack at the boundary and it will look wrong forever. Do the reverse and you have put a thin acrylic skin over a wall that needed structure.

That is why the first thing worth establishing on any quote is which system you actually have, and it is a question a competent contractor asks before pricing.

What each costs

Traditional, from the published pricing page: crack repair $200–$800, patching $500–$2,000 or $8–$15 per square foot, recoat $3–$6 per square foot, full restucco $6–$9 per square foot.

Synthetic and EIFS varies more, because the systems vary and because the question of what is behind the foam has to be answered. Small impact repairs are modest. Anything involving moisture behind the foam means opening it up, checking the sheathing and framing, and rebuilding the system properly, which is quoted after inspection rather than from a rate card. We will tell you honestly which of the two you are looking at before quoting.

Living with EIFS well

It is not a bad system and there is plenty of it here working fine. What it wants:

1. Keep the sealant joints maintained. Around windows, doors, penetrations, and at terminations. These are finite-life items and they are the main entry route for water.
2. Keep irrigation and splash-back off the base. Sprinklers hitting a wall is bad for any system and worse for this one.
3. Keep grade below the termination. Soil or mulch built up against EIFS is a direct moisture path.
4. Deal with impact damage promptly, because a puncture is an open door.
5. Check after hail. Hail events in this metro do real damage to synthetic finishes, and it is worth documenting.

What to expect on the call

A photo of a window return or a corner, which usually settles which system you have, plus photos of the damage and one from further back. Tell us the age of the house and whether it has been repaired before. We cover Rio Rancho, Corrales, Bernalillo, Placitas, Albuquerque, and Los Ranchos.