The expander is vulcanised on both sides and is suitable for installation between half round gutters.
The rubber is covered up in the visible area.
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Gutter expander - with cover - half round

Not available in all sizes

The expander is vulcanised on one side and suitable for installing in half round gutters.... more

Gutter expander - half round

Not available in all sizes

The expander is vulcanised on both sides and suitable for installing between box gutters. The rubber is covered in the visible area.... more

Gutter expander - with cover - box shape

Not available in all sizes

The expander is vulcanised on one side and suitable for installing in box gutters.... more

Gutter expander - box shape

Not available in all sizes

The tape expander is a custom solution for all self-trimmed profiles and gutters. ... more

Tape expander

Not available in all sizes

The single-head expander for installing in flat roofs. It’s used on long eave rims and edge trims that are stuck or welded in.... more

Single-head expander

Not available in all sizes

GRÖMO's Universal Channel Dilatation is a true all-rounder. Whether initial assembly or repair of old and brittle movement compensations. The Universal Dilatation can be easily glued into any semicircular channel. The corrugated dilatation area of the EPDM rubber reliably compensates for material expansions of up to 50 mm and prevents the dilatation from throwing up in the watercourse. The Universal Dilatation can easily be cut to the right gutter size. Simply grind and clean the gutter, attach the bead trim, glue - done.
The separately available bead trim provides effective protection against the ingress of water and dirt into the movement compensation.
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Universal Gutter expander half round

Not available in all sizes

The bead trim is required as the upper cover trim for gutter dilatation. Through the orifice plate the precipitation water is led into the gutter and cannot penetrate behind the movement compensator.... more

Bead trim

Not available in all sizes

Gutter expander from GRÖMO – Always in motion.

No tension here, guaranteed.

All materials against and on the roof are exposed to especially severe temperature fluctuations. It is not uncommon for the change between hot and cold to be volatile. During storms, for example, it can grow colder by a couple degrees within a few minutes. But in the early part of the year, it also often occurs that bright sunshine by day turns into frost in the night. In addition to that are also different regional factors like sun exposure and shadows, which also change the expansion behavior of the individual components. In order to head off material stretching and prevent tension in metal, expanders, also known as expansion compensators, are installed in roof gutters. Without dilatation elements, temperature fluctuations can severely damage the gutter or the gutter corner, leading to high costs. Soldered seams and adhesions of bitumen sealing membranes are especially threatened by this stretching of the material. GRÖMO motion compensators can be installed into any given profile by soldering or welding in, without a problem.

Please keep distance.

When it comes to determining the optimum distance between two expanders in a gutter, there are different aspects to keep in mind. First, it depends on what type of roof gutter it is. Is it a suspended or an inboard roof gutter? Then it’s important to know if the cut is under or above 500 mm. Depending on the type and material design, the required distances between the individual gutter expanders can be between 6 m and 15 m.

Gutter expander installation instructions

While installing motion compensators, make sure that the sheet metal in front of the rubber as well as the rubber middle part are covered with a wet towel so that no heat can transfer to the rubber middle part. You should maintain a minimum distance of 6 cm to the middle part of the rubber. It should never come into contact with open flame.

What to pay attention to when laying tape and head expanders:

The bending bar should have a minimum radius of 2 mm when beveling and installing. In addition, a bending radius of 5 mm must be attained for sheet metal that is 1 mm or thicker. The folding beam should be lowered 3-4 mm according to the thickness of the rubber middle part, to avoid being sheared. It’s important that the rubber middle part not be crushed or damaged. Therefore an aluminum metal strip, 205 mm thick, should be trimmed so that it can be put on the folding beam like a shoe. This will give you a bigger bending radius and prevent the rubber middle part from being harmed. Optionally, you can also use a bending machine with segments.