Do expansion joints require reinforcement

DIN 18195 part 8 seals over movement joints

A distinction is made between two types of joints depending on the frequency of movement:

Type I joints:

For slow and one-off or infrequent repetitive movements such as changes in length or settlement movements due to seasonal temperature fluctuations.

Type II joints:

For fast or frequently repetitive movements such as changing traffic loads or changes in length due to temperature fluctuations during the day.

The dimensions of the joint movements according to DIN 18195-8, 7.1 must be observed.

Sealing against soil moisture

Type I joints with movements of up to 5 mm:

Seals over joints in surface sealing made of bitumen materials must be reinforced with at least one layer of bitumen sealing or welding sheeting (300 mm wide), with a fabric or polyester fleece insert.

Sealing over joints in surface sealing made of plastic-modified bitumen thick coatings are embedded in the bitumen thick coatings with bitumen-compatible joint tapes made of plastic sealing sheeting with fleece or fabric lamination.

Seals over joints in the case of surface sealing made of bitumen KSK membranes must be reinforced with an additional strip (300 mm wide) made from bitumen KSK membranes.

Seals over joints in the case of surface seals made of loosely laid plastic or elastomer sealing sheeting may be pulled through the joints without further reinforcement.

Type I joints with movements greater than 5 mm:

Like joints type I with movements of more than 5 mm, they are to be used to seal against non-pressing water on ceiling surfaces and in wet rooms.

Type II joints:

Like type II joints, they are used to create seals against non-pressing water on ceiling surfaces and in wet rooms.

Seals against non-pressing water on ceiling surfaces and in wet rooms

In order to prevent the waterproofing from sinking into the joint gap, the waterproofing over the joint may have to be reinforced (e.g. with support plates).

Type I joints with movements of up to 5 mm:

Sealing according to DIN 18195-5, sealing with membranes for moderate and heavy use, are carried out over the joint. If necessary, drag strips with a minimum width of 100 mm are to be arranged under the waterproofing. In the case of loose laying with an effective separating layer, this may be omitted. In the case of glued seals, reinforcement with a minimum width of 300 mm of the same sheeting material must be arranged.

Seals according to DIN 18195-5 with asphalt mastic are interrupted above the joint. This joint must be grouted and a drag strip at least 100 mm wide must also be arranged. The waterproofing must be replaced over the joint with at least one bitumen or polymer bitumen sheeting with a polyester fleece or fabric insert with a width of 500 mm in the event of moderate stress, and at least two in the case of high stress.

Over building joints with seals according to DIN 18195-5 with bitumen welding sheets in connection with mastic asphalt, the seal is to be reinforced with a second layer of the same sheet type with a width of 1000 mm. The mastic asphalt layer may be pulled through without interruption.

Seals according to DIN 18195-5 with plastic-modified bitumen thick coatings are to be carried out like sealing against soil moisture, joints type I with movements of up to 5 mm.

Type I joints with movements greater than 5 mm:

The waterproofing of surface waterproofing made of bituminous materials is pulled through the joints and must be reinforced with one or two 300 mm wide strips of bitumen and polymer bitumen sheeting with a polyester fleece insert, or bitumen-compatible plastic and elastomer sealing sheeting.

Seals with bare bitumen sheeting can also be reinforced with a stainless steel or copper tape.

Plastic or elastomer sealing sheets as surface sealing must be pulled through in the joint area and supported with plastic-coated metal sheets or external joint tapes to be embedded in concrete.

Surface waterproofing made of bitumen KSK membranes must be reinforced over the joints with strips of the membrane on top and bottom.

Special constructions are required when sealing with plastic-modified bitumen thick coatings.

Type II joints:

The type of waterproofing must be determined on a case-by-case basis, taking into account the frequency and size of the joint movement (e.g. by arranging waterstops or prefabricated joint constructions).

Seals against external pressurized water and temporarily accumulating seepage water

Type I joints, water pressing from the outside:

In the case of surface waterproofing, the seal is pulled through the joints and must be reinforced with at least two 300 mm wide strips of copper tape, stainless steel tape or plastic or elastomer sealing sheeting. Table 1 applies to arrangement, number and size, reinforcement strips and joint chambers for type 1 joints.

If only two strips are arranged, they must always be made of metal. These are to be arranged on the outside of the waterproofing and protected with a bitumen sheeting.

In the case of loosely laid plastic waterproofing membranes, the seals over the joints must be supported, reinforced and welded with four-bar joint tapes.

Joints type I, intermittent seepage water, movements up to 5 mm:

Sheets for the execution of seals against accumulating seepage water are pulled through the joints and reinforced with a supplement of the same type of sheet with a minimum width of 500 mm.

Seals according to DIN 18195-6 with plastic-modified bitumen thick coatings are to be carried out like sealing against soil moisture, joints type I with movements of up to 5 mm.

Joints type I, intermittent seepage water, movements over 5 mm:

The sealing over the joints is to be carried out like type II joints in the following.

Type II joints:

Basically, the seal over the joints is to be made with special constructions (e.g. with loose and fixed flange constructions according to DIN 18195-9).